A low situation

We were asked whether a garage in Ely, barely 3.5 metres high, would be suitable for Swift boxes, so we decided to give it a go. It is only by trying these things will we ever find out whether it is something to recommend or not.

There happened to be one stretcher brick, centrally placed and high up in the gable - it is the highest point that one could practically put an entrance. It is a double thickness wall, the inner leaf being breeze blocks.

One brick containing 2 entrances was cast out of 50:50 sand/white cement mixture.

A double box, each with floor area 20cm x 25cm,
and double entrance piece cast out of 50% sand, 50% white cement

A cardboard template was used to determine the shape
 of the separator between the boxes and entrance piece

Entrance piece mortared in. When the mortar is dry it will be a nice match.
The mortar is a 4:1 sand/cement moxture

2 internal boxes with inspection doors.

5th International Swift Conference - Tel Aviv 11th - 15th March 2018

Following the 4 successful Swift Conferences in Berlin (2010 and 2012), Cambridge (2014), Szczecin (2016), the 5th conference will be held in Tel Aviv, Israel, 11th-15th March 2018

As well as conference sessions, there will be organised trips to local birding and Swift hotspots, including the Swifts Welcoming Ceremony at the Western Wall in the Old City of Jerusalem.

Optional extension tours, including to Eilat are offered up to 20th March.

Full details of the conference and tours and how to register can be found here:

http://telavivswiftconf.canalblog.com/

There is a direct link to the attendees here

Internal boxes with cement board

This project at Bob & Elaine Humphrey's house in Landbeach, Cambridge gave the opportunity to try something new - nest-boxes made out of cement board.

by Bill Murrells and Dick Newell

Most retrofit projects using the Cambridge System have had the nest box wholly inside the roof space. In this project it was preferred to have the boxes spanning the cavity, embedded in the inner leaf of a cavity wall. The boxes extend only a short distance into the roof space. Boxes this high up under eaves in a roof space are not going to have damp or cold spot problems.

Any commercial nest box would have needed a larger hole in the inner leaf and would need to be modified with an inspection door, so we went for the DIY approach. Although treated quality plywood in this situation is probably perfectly OK, we thought we would give a recognised building material a go.

We chose 12.5mm Knauf Aquapanel Exterior Cement Board, never having used it before. This is a high quality product, about twice the price of 12mm plywood. We bought a 90cm x 240cm sheet - sufficient for 12 internal boxes. We made 6 boxes for this project, 3 in the south gable and 3 in the north.

The material was cut using a small tungsten-tipped hand saw. This gave a good finish.

As the cement board could not easily take a screw without cracking, the whole thing was glued together (we used Hippo Pro 1). We constructed the back of the box, with a hinged door out of 12mm plywood. The hinges are 'piano' hinges

The boxes have an internal floor area 22.5cm x 22.5cm and headroom 15cm.

A hole was cut with a masonry drill and a handsaw through the inner-leaf slightly larger than the box cross-section: 25cm x 17.5cm.

The following pictures explain how it was done:

2 boxes complete. The entrance piece has been stained with tea. 

3 rectangular holes in the inner-leaf and 1 box in position. 

3 boxes mortared in. 

3 nicely positioned entrances under the eaves, facing south. Space is made for the entrances by trimming 56mm off the ends of adjacent bricks each side of a vertical bond. This is achieved by drilling a line of small holes with a masonry bit. A hammer and chisel is not used as this would risk cracking the brickwork.

A House Martin's nest, occupied in 2017 and 3 Swift entrances in the north gable

#Cambridge

#internal

GRP Swift box installation

We earlier described (here) a new multiple Swift box from Impeckable made of GRP (Glass Reinforced Plastic). It exploits the boat-building skills of Len Haworth, and has advantages of light weight, water resistance, sun resistance and a long life.

Since then, Len has sent the above pictures of an early installation, as well as a new development, a canopy to provide protection from the sun, below.

Although a very modern product, it blends in well with an older architecture.

In a gable apex like this, there is the potential to stack a 2-box over a 4-box over a 6-box to make a triangle.

The pictures below show the new canopy.

For more information visit http://www.impeckable.co.uk/

A successful Polish Swift tower design

Although many Swift towers have been erected, few have more than a pair or 2 of Swifts. We were therefore impressed by this design, the "Jerzykowniki” tower, which has been erected in 13 locations in Poland, 5 of which have acquired new occupants in the first year or two.

This story was sent to us by Katarzyna (Kasia) Szczypa

The tower “Jerzykowniki”
Lidzbark Warmiński (Warmia-Masuria region)

Following the erection of a stork platform, which, not unexpectedly, had failed to attract any storks to central Warsaw, the Stork Nature Society decided instead to design a tower suitable for Swifts, House Sparrows, Starlings and Tits.

All of the photos in this post are taken by Adam Tarłowski (ornithologist and designer of the tower from ussuri.pl), and Mariusz Grzeniewski (ornithologist from apusmg.pl) who have been protecting Swifts for 10 years.

A total of 13 “Jerzykowniki” Swifts towers have been installed since 2014 in Poland. Seven towers in Warsaw and six in other locations were set up in areas such as parks and among blocks of flats. Mariusz and Adam together with the Stork Nature Society control 11 of them.

The tower “Jerzykowniki”
in Warsaw (Bielany district)

Successful breeding pairs were found in 5 towers. One of them, 2 years after installation, had 4 breeding pairs in 2016 and 6 pairs in 2017. This was achieved without playing attraction calls!

The remaining 4 towers had one breeding pair each in 2016. The tower is not only effective, it is also an attractive design.

Each tower has 24 nest chambers arranged in a hexagonal structure with 6 chambers on 4 levels. Various hole shapes and sizes are included ranging from sizes suitable for tits to sparrows and starlings. A simple narrow door on each of the 6 sections allows for inspection and maintenance.

The drawing below, by Adam Tarłowski, gives indications of overall dimensions.

Footnote: Jerzykowo is a Polish town.

An adult Swift and 2 Swift chicks on top of a House Sparrows nest

Thoughts on concave design

It is not unusual for eggs to move out of Swifts' nests. Sometimes an adult will deliberately pick up an egg and dump it outside the box. However, other times it seems to be accidental as some Swifts have been observed on webcams moving eggs out, either by shuffling or with the head while adjusting nesting material.

We have already shown conclusively that Swifts prefer nest boxes with a concave (here). Although Swifts appear to be most comfortable as they snuggle down in a deep concave, are concaves made by a spherical scoop, with a sloping periphery the best shape?

These thoughts were prompted when swifts in one of my daughter's nest boxes with a concave scoop 85mm diameter and 22mm deep, 2 eggs were moved out in 2016 and then 5 eggs in 2017.

We all know that Swifts are individuals and maybe some Swifts are more clumsy than others, but when this particular concave was replaced by one with a vertical periphery and a shallow depression in the bottom, they went on to incubate the 5th and 6th eggs, hatching one of them (which, at the time of writing is doing well). The replacement concave extended for the whole width of the box.

A discussion on SLN yielded the following experiences:

David Makin had a similar experience to the above with Swifts displacing 4 eggs in 2016 and another 4 in 2017 from a concave 22mm deep, before finally laying a replacement clutch of 2 eggs which they went on to hatch.

Brian Cahalane makes his concaves out of a 30mm thick piece of wood in which he cuts a 100mm diameter hole. The bottom is therefore flat, but Brian paints the bottom with glue and then throws a handful of feathers in. Anything with a flat bottom is not going to cause the eggs to move to the centre, but the feathers may well provide the necessary shape for this. Brian never gets eggs displaced from these concaves, but he has had a small number of eggs displaced from shallower concaves over the years.

Mark Glanville has this experience:
"My scoops are not really cups but made from off-cuts to fit exactly into the box with no gaps between them and the sides. Most of my boxes are 8" wide so I tend to use a piece of wood 8" by 8". They are all homemade with 100mm diameters and I use wood filler to make the edges of the concave smooth. I aim to have at least 2" clearance between the concave and the sides/back of the box. I am sure that having it all on the same level has helped reduce the number of eggs/young being flicked out on changeover duties. The concave depth varies between 12mm and 22mm. No reason for this other than I use the same wood left over from building the box. One thing I do add on the 12mm scoops is a bead of mastic (2-3mm high) around the rim of the concave to give it a bit of a lip. All my scoops are lined with feathers with extra being added around the rim. 

Louise Bentley comments that the Swifts do look most comfortable in her concave, but still they pushed one egg out on their first breeding attempt, which hatched after being replaced by Louise.

Tanya & Edmund Hoare agree with Mark and suggest that more horizontal space around the concave could help, and suggest that a concave in the floor of the box could be a solution.

To add to the above, I have measured a number of natural nests. They are about 85mm diameter, and depth up to ~20mm, and usually the periphery is a wall of feathers. It is not unusual to find a natural nest wedged into a corner or side of the box. There is little in the way of any horizontal surface outside the periphery. Some nests can be quite high.

So what does one conclude about this?

Concave scoop tool

The diameter of a Swift's egg is ~16mm, so any "cliff" over about 8mm should keep the eggs in. 

Therefore I would conclude that a concave with a vertical periphery at least 10mm high (say) and some sort of depression in the bottom is ideal. The depression can either be achieved by machining the right shape (suitable for a product) or by gluing feathers in the bottom (suitable for the DIY enthusiast).

Concave made of Kingspan wall insulation

Whether sticking feathers to a concave is worth doing is not known, the experiments have not been done, but certainly feathers scattered in the nest box are readily used by Swifts.

Some horizontal surface around the concave may be a good idea.

As a next step I have had a tool made to make vertically sided shallow scoop concaves with a diameter of 85mm.

The pictures above show the tool and a prototype concave made out of insulation (yes, it is highly inflammable) coated with PVA glue to resist Great Tits and House Sparrows. 

The attraction of this material is that it is very easy to machine.

These concaves are so light that they do need sticking down.

I have had a number of concaves made of this material in boxes over the winter, and none have been damaged so far. The next step is to see what Swifts think of them.

[UPDATE June 2018 - we found 3 concaves heavily damaged by Great Tits - so this idea is now abandoned]

Update January 2018
Using a sheet of 12mm soft fibreboard, cut into 12cm squares - one can get 200 squares out of a 2440 x 1220 sheet costing about £14. This will make 100 concaves - so 14p per concave.

We used an 85mm hole saw to cut a hole in one square, then glued it to a second square.

Then scoop out the second square with the tool described above.

As most of the material is removed by the hole saw, there is far less dust.

The result looks very good - vertical sides to keep the eggs in and a concave bottom to keep the eggs in the middle.

The finished product is coated in PVA glue to deter Great Tits

85mm hole saw, concave and scoop tool

New Swift boxes at Lowgill

In 2013 we reported on developments at Tanya & Edmund Hoare's Lowgill house. Over the years, this has developed into 4 Schwegler 25s Swift bricks, 6 Zeist boxes, and most notable of all, 10 custom internal spaces in the eaves that are viewable from the bathroom and bedrooms! This post describes a major extension of the nest sites available with internal boxes in the gable.

by

Tanya & Edmund Hoare

We have swifts nesting in our eaves at Lowgill, Cumbria and four pairs in Schwegler 25s bricks in the gable that we installed 7 years ago. Those, in the gable end, were all occupied in the first year and have always been by far the most popular place with bangers. So last winter we decided to create a further 12 sites in the gable, using the Cambridge System similar to that at Fulbourn, with entrance pieces linked to internal boxes in the loft by 4” drainpipes.

Demolition of the 2' thick chimney breast

The gable wall consisted of a redundant chimney breast 2ft thick. As Swifts may be less willing to navigate a pipe 24" long, we decided to rebuild the gable with a narrower wall incorporating 12 pipes 12 inches long.

A platform of mortar was put into the pipes so that the swifts could get a grip when they crawl along.                

Former with cast entrance piece

Custom made entrance pieces were made by making a mould and using formers kindly made by Dick. They were coloured to match the sandstone walls. An attraction call system was installed with the loudspeaker in the apex of the gable.

Wooden nest boxes were fitted in the loft, each with a camera. Shelves were put up on the inner wall for the boxes to rest on so that they could easily be removed if necessary.

While the house was scaffolded we decided to also install another 2 Schwegler 25s at the edge of the gable where we couldn’t use the pipe system.

The end result is aesthetically more pleasing than using commercial bricks. 

Already in the first season we’ve had success, with both the new Schweglers occupied by roosting pairs. Bangers have approached the new holes although so far none have gone in, but fingers crossed for next year.

Rebuilding the wall 12" thick with embedded pipes and entrance pieces

The completed wall with 12 entrance pipes

Shelving support 12 nest boxes behind each pipe.

The finished wall on the outside showing the new Schwegler 25S boxes lower left and lower right, the original 4 Schwegler 25S's and then the 12 new Cambridge System entrances. Although the half-brick entrance pieces are normally used in a brick wall, they don't look at all out of place in a stone wall.

#Cambridge

Entrances made by cutting bricks

We no longer recommend that people make an entrance to an internal nest box by cutting bricks, unless you know what you are doing. This is because of a number of experiences of getting the wrong size, both too small and too big. Here is an example of how to do it properly.

The tolerences for the smaller dimension of a Swift entrance are rather tight. Too big will let Starlings in and too small will make it difficult for Swifts. The longer dimension of the entrance is not critical. Perhaps a minimum of 50mm, often set at 65mm and bigger than this is OK.

Starlings can squeeze into 30mm. The smallest dimension that a Swift can squeeze into is ~25mm. So we recommend 28mm ± 1mm

In Kev Gray's own words:

"... I ended up cutting a very accurate slot to your dimensions into the top face of a matching house brick. I used a stone cutter in my 9 inch grinder, it didn't take many minutes, I bonded a slate lid over the top of the cut out and fitted the whole brick. If one uses mortar to fashion the 4th side of the entrance, there is much scope for getting it wrong. Prefabricating the entrance ensures the correct size.

First we cut the brick out of the wall, we used a battery powered masonry drill and bit and just drilled a series of holes all the way around the brick and it came out quite easily.

The hole was then tidied up with a bolster chisel and the swift brick fitted.

A long masonry bit was positioned in the centre of the Swift slot from the outside of the wall and guide hole was then drilled through the inner wall, the wall on the other side of the cavity, this is usually breeze block and drills very easily.

From inside the loft.

The guide hole previously drilled in the breeze block is then used to guide a large diameter masonry hole cutter, if it's breeze block it cuts quite easily, if you don't have access to a hole cutter you could use drill a series of small holes drilled in a circle and chisel the middle out.

When the hole is finished measure from the internal face of the breeze block back to the inside face of the Swift brick to establish the length of soil pipe required.

The pipe is just ordinary 110mm soil pipe, anything similar would do, you can get it from most DIY stores., I can be cut with a hand saw and positioned into the hole so that it butts up to the new swift brick, take care if the mortar is still soft as you may dislodge the swift brick, it's better to leave it time to set. When the pipe is in position use some mortar to fill in any gaps and holes that may be in the swift brick to make a nice smooth passage without any sharp edges. Also it's a good idea to put a bed of mortar along the bottom run of the soil pipe as this will help the Swifts have a bit more grip onto what would otherwise be a very slippery surface. In fact it's a good idea to give the inside of the soil pipe a good roughing out with some course sandpaper before putting it into position as this will help the mortar stick.

As mentioned earlier, I made up a couple of boxes from some spare 18mm chipboard floorboard because that what I had handy, but you could use something much thinner maybe some plywood. Bill Murrells recommend internal dimensions of W 200 x L 300 x H 150 for the box and that is what I went with.

Removing a brick

Components of the entrance brick, before cutting

Relative positioning of soil pipe and entrance brick

The completed entrance

A view from the inside

Another triangular cabinet in Elsworth

In 2015 we installed a 3-box triangle on my daughter's sunny gable end (here). It is now occupied by 2 pairs of Swifts so we wondered how to expand the number of boxes

There were 2 choices, either to add a 3rd row of 3 boxes at the bottom of the triangle, or to make a new cabinet on another northeast-facing gable. This gable is wooden-cladded and has an apex nearly 5 metres high.

As there should be no over-heating to deal with, the front is a single sheet of 12mm plywood and is painted dark to match the gable.

This is the 4th triangle of this general concept that we have installed, the other 3 all have Swifts in them.

The slope of the roof is less steep than the other 3, so the headroom of the boxes is slightly less at 14cm, and the length of the boxes is slightly greater. The depth of the boxes is 15cm.

Front removed ready for installation

6 screws through the back secure the cabinet to the boards

The lowest 3 boxes are just over 4 metres high

[Update June 2018: One pair has occupied the bottom right chamber, the one nearest the tweeter]

#triangle

Swift boxes at the David Attenborough Building

The David Attenborough Building (DAB) in Cambridge houses conservation practitioners and academics, who are working together Cambridge Conservation Initiative (CCI).

"The David Attenborough Building will act as a collaborative hub for the conservation community within Cambridge and beyond - Mike Rands"

[Update 2021: an inspection before the season found one box had been occupied by Swifts. A camera was installed and the images of the breeding Swifts were streamed online. A second inspection at the end of the season revealed 3 occupied boxes]

It had always been the ambition of the executive director, Mike Rands, to have breeding Swifts, so AfS was invited to see what might be possible. As all the building work had been finished, this was a retrofit situation on a very smart building that we would not want to compromise in any way.

Two opportunities presented themselves: boxes installed at the top of one of the towers and boxes on the parapets. As the former would be less visually intrusive, Mike suggested we go for the towers.

The tops of the towers are octagonal with vertical bars containing 4 of the sides. The bars are 50mm wide and spaced 50mm apart (see pictures below).

John Stimpson supplied 8 Model 30 nest boxes, but with no entrance in the front. This was a suitable choice as the top of the tower is exposed to the sky, so the boxes may receive both rain and sun.

For the Swifts to gain access to boxes inside the bars, it would require tunnels about 15cm long to the outside.

We have some anecdotal evidence that Swifts will not negotiate a small tunnel of this length (e.g. here). Thus we made tunnels with inside dimensions 43mm wide x 65mm high.

A D-shaped hole was cut in the back and tunnels fashioned out of roofing plastic glued in place.

Roofing plastic put into boiling water is easy to shape around, in this case, an empty can of hairspray.

Rubber strips provided separation and friction between the boxes and the metal bars.

The tunnels could also provide access for Starlings, so the top part of the tunnel is blocked on the inside face of the box. This should leave enough space for a Swift to enter, but not a Starling. One of the concerns was not to have bird droppings down the building.

The brackets, made of stainless stud and aluminium bars, were made by Dexter Bullman of Landbeach. They were painted to match the vertical bars.

A Cheny Heny MP3 player was installed driving 2 tweeters facing outwards below 2 of the tunnels. We gave some thought to the possibility of Swifts coming through the bars, but as the space is open to the sky, they should be able to get away.

The pictures below illustrate what was achieved:

4 tunnels outside the SW side and 4 boxes inside the SE side

Close up of the 4 tunnels on the SW side

Installation team: Bill Murrells, Elizabeth Allen, Collaborations & Communications Manager,
Dexter Bullman and Mike Rands, Executive Director.
Dick Newell took the picture

Headroom experiment at Greys Farm

Greys, near Royston, Herts is where Edward Darling uses 2 sq km of chalk soil to create a living landscape benefitting many forms of priority wildlife, including a wide range of birds, mammals and rare plants. The BTO Marsh Award to Action for  Swifts lead to Edward enquiring about creating Swift colonies and asked if we would suggest where Swift boxes might be appropriate.

[Update 23rd June 2017 - the first Swift has been seen entering box number 4]

At the highest point of the farm is a water tower, a cube-shaped, steel-clad building containing water tanks. It is somewhat isolated, so not the normal setting for Swifts, but the building itself has boxed in eaves on the east and west sides which are plenty high enough and wide enough for Swift boxes. It also has mains power inside.

So against a background of singing Blackcaps, Chiffchaffs and Whitethroats we installed nest boxes on the east side, under the boxed in eaves.

Edward is also Chief Executive of Redlist Revival, a UK based charity working to restore disappearing - "Red-listed" - species identified within the Government's UK Biodiversity Action Plan. Forming part of the country's international commitment to maintaining ecosystems and sustaining a healthy planet, Redlist Revival acts for the public benefit.

We are using this project as an experiment, giving Swifts a choice between boxes with 150mm headroom and 78mm headroom. A single-brick nest box would be 78mm high.

The 12 boxes are all basically the same, with entrances at the left or right end. As we could not decide whether to put entrances facing horizontally or vertically downwards, we used a compromise. The floor area of the boxes is 266mm x 200mm. All the odd-numbered boxes have a removable false ceiling.

We have previously set up experiments like this, including this one which has had some success.

The 12 boxes are arranged in an irregular, but neat pattern. 
This is done to reduce confusion for the Swifts 

All of the boxes are uniquely numbered 

Odd-numbered boxes have a removable false ceiling, painted black 

Swift boxes at Cley Nature Reserve

When it was suggested to Richard Porter, a Cley resident and Trevor Williams an energetic volunteer with the Norfolk Wildlife Trust that it might be a good idea to have Swift boxes on the visitor centre, they quickly responded by getting approval from the powers that be.

However, when we came to look for suitable places for Swift boxes, there was nowhere that was ideally suited. We originally thought that the Simon Aspinall Education Centre would be the most appropriate - Simon was a great fan of Swifts, and would have loved the idea. However, it is adjacent to the public area where people have their picnics in the summer, so attraction calls so close might not be appreciated by all visitors. Also the building is quite exposed.

As a result we settled on the Dick Bagnall-Oakeley Centre, an attractive thatched building, clad in timber and with broad eaves. However, the eaves are only 2.8 metres high. Although this is well below our very minimum recommendation (~3.5 metres), Swifts are known to nest at this height and lower. (see here and here) The ground in front of the building slopes away from the building, overlooking Cley Marsh, so this might help
.

Trevor Willlams installing a Model 30 Photo Richard Porter

The net result is that we installed 4 Model 30's supplied by John Stimpson. The geometric shape of the Model 30 fitted the underside of the eaves perfectly.

Should this plan succeed in attracting Swifts, then there is scope to expand to double or treble the number of boxes.

We regard this project as pushing the boundaries - although it challenges our own advice, it may tell us something.

Trevor Williams and Richard Porter with 4 Model 30 nest boxes

A Swift tower at The Avenue Washlands

Back in 2011, we posted an idea for a Swift tower, based upon four 4-box cabinets, so 16 nest chambers. Since then, we have installed a fair number of 4-box cabinets, many of which have between 1 and 4 pairs of Swifts in them, but we never built the tower. Now, volunteers from the Derbyshire Wildlife Trust have extended the concept and executed an excellent example with 24 nesting chambers.

The Avenue Washlands is a Derbyshire Wildlife Trust wetland reserve consisting of reedbed, marsh, ponds and grassland in the valley of the River Rother, near Chesterfield. Along with the installation of pole-mounted Barn Owl boxes, they have now successfully installed a pole-mounted Swift Tower.

The project was funded and built by members of the Chesterfield & NE Derbyshire Local Group of Derbyshire Wildlife Trust. For the installation they were helped by the reserve’s Sunday work party volunteers.

The body of the boxes is made of pressure-treated timber. The roof and backs are made from Tricoya which claims to have an exterior life of 50 years! The roof has a ridge made from guttering.

The pole was donated and erected by Western Power. It is the most impressive pole that we have seen in terms of its size and rigidity, and gives a sense of proportion to the whole structure.

A solar panel driven attraction call system will be installed ready for the 2017 season.

We thank Brian Goodwin and Nick Brown for sending us this story and the pictures.

The tower is assembled from 2 each of these components

A test assembly on the ground.

Assembly in progress by reserve volunteers

A great-looking end result

A new Swift box in GRP

GRP (Glass Reinforced Plastic) is a waterproof material normally used for making boats, car bodies and other products which need to combine strength with light weight. So, Len Haworth decided to apply his boat building skills to produce a range of rather nice looking, very long-lasting Swift boxes.

In his own words:

"Since 2003 I have been using my boat building skills in GRP for the good of the birds. My company www.impeckable.co.uk does not make a profit, any surplus either goes on development for more species or to buy the expensive materials which go into each box. But then I thoroughly enjoy what I do. Before I start the development of any nest box, which is a long and expensive business, I have to get the basic design spot on because later alterations are not possible with GRP (Glass Reinforced Plastic). I have consulted with ornithologists such as Chris de Feu, who I greatly value as an advisor and where it comes to Swifts, Edward Mayer of swift-conservation.org and I have had a long exchange of emails to get the basics correct. "

Certainly the first Swift boxes off the production line look the business. One can see the nautical heritage in the porthole-style entrances. All the fittings are stainless - as Len "does not do rust". For south-facing aspects, exposed to the sun, Len is producing a canopy to deflect the sun.

Each nesting chamber has dimensions; 300mm long; 200mm wide; 200mm high

The oval nest concaves are a novel idea, it will be interesting to see what Swifts make of them.

Boxes are available in 1, 2, 4, 6 and 8-chamber versions.

For further information and prices, download this leaflet 
Also visit www.impeckable.co.uk