For sale, one Cocoon 4 Extreme sleeping bag with bivi canopy.
$1,700 + shipping from UK.
This is a very rare item - the last one sold on e-bay was 2 years ago.

The Cocoon 4 Extreme is probably the warmest sleeping bag ever made. It is unique amongst sleeping bags in being inflatable. It has a 6 inch thick down filled inflatable mattress, topped with a 6 inch thick down filled inflatable blanket. The thickness of the blanket is adjustable to vary its insulating power to cover a range of temperatures from -45°F to +70°F (-42°C to +21°C). The sleeping bag is fully waterproof (some daring owners have experimented floating on water). It comes with a high performance canopy turning it into a complete sleeping system and removing the need for a separate tent / bivi and mattress. The canopy uses carbon fibre poles and titanium pegs. Their US manufacturer went bust in 2002. I bought a Cocoon 4 Extreme (their highest spec) in 2001 with a view to distributing them in the UK. I never did end up distributing them and it has been used for six nights. 4 cold nights on snow photographing glaciers in the Andes. 2 nights in the Pyrenees.

cocoon 4 sleeping system
It is near new condition having been stored uncompressed, in cool dark conditions since it was purchased. Only a few hundred of these bags were made before Pneugear went bust. Its been 2 years since the last one came up for sale on eBay.
This bag is 15 years old. Its in near new condition, but in those 15 years have other sleeping bags caught up? The answer is “not yet".
Traditional sleeping bags lose their insulating properties dramatically from compression and condensation.
Traditional sleeping bags use down or synthetic fibre that ‘lofts’ to create air gaps and insulate the sleeper. However the weight of the person in the bag compresses this insulating material, removing the air gaps and therefore its insulating properties. The Cocoon solves this by using an inflatable down filled mattress. You get all of the insulating power, all of the time. A 6 inch thick air bed is also incredibly comfortable. Since the cocoon, other companies have started to make down filled inflatable sleeping mats, like the Exped DownMat XP 9. These are fantastic but at 3.5” they don’t match the 6” of down in the cocoon. The cocoon was also innovative in building this right into the sleeping bag itself so that you didn’t have the weight of a sleeping mat plus the bottom half of a sleeping bag. Bags like the Eddie Bauer Air Bender do now integrate an inflatable mattress into a sleeping bag but again the mattress is only a fraction of the thickness and warmth and comfort of the cocoon.
Traditional down bags used in extreme cold over multiple nights, build up condensation in the bag. Perspiration from the sleeper condenses in the sleeping bag. This destroys its insulating properties and adds potentially kilos of extra weight as water and ice. The cocoon solves this by making both the bottom (mattress) and top blanket air tight and therefore impermeable to moisture from the occupant. So your bag is as warm on the last day of your expedition as it is on the first. VBL or vapour barrier liners address this too and have grown in popularity. They keep the humid air around your body and prevent it from going into the down insulation of regular bags. However for you to be comfortable inside the sleeping bag while using a VBL you need the insulation level of the bag to match the temperature outside and the problem with all sleeping bags on the market today (with the exception of the Nash Frostbite Wide Boy) is that only have one insulation level. If the bag is not insulating enough,you’ll be cold. If the bag is too insulating, you will perspire faster than your body can re-absorb that moisture. (note that a little know fact, is that the body does absorb moisture as well as expire it). The Cocoon is unique in being able to vary the insulation level of its blanket by inflating it to different thicknesses. Fully inflate to about 6” for maximum insulation for the coldest nights. Empty it of most air if its a gentle balmy night.

Worth a read are the customer reviews at Trailspace.
http://www.trailspace.com/gear/pneugear/cocoon-4/

Here are some photos I've just taken:So there it is. This incredible bag needs someone to take it on some big adventures.
Although Pneugear is no longer in business, you can look at their archived website here: http://web.archive.org/web/20010214035553/http://www.pneugear.com/index.html
and I have copied some of the pages below.
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See Inside the COCOON 4
THE WORLD’S BEST 4 SEASON SLEEPING SYSTEM
“In 30 years of testing, we have never seen anything like it! The COCOON 4 is the best sleeping bag in the world.”

Ralph Goldman, Ph.D.
Chairman of the NATO Committee that compared sleeping bags of all NATO countries, and Director (ret.) for over 20 years of the Army group that does sleeping bag evaluations.
“The COCOON 4 was very warm and comfortable in the advanced base camp at 18,000’ on the Tibet side of Everest”

Steve Kin

“The best night’s sleep I’ve had in over 40 years of camping. Even the winds of Baja didn’t phase it.”

Wayne Marsula’

“We have tested all the leading equipment, under the harshest conditions, for Polar Challenge. Even at -40° F, in high wind, we were cozy in our COCOON 4. It is unquestionably the best there is.”

Helen Thayer

INFLATABLE
The COCOON 4 uses air pressure to control the loft of the 650 fill, premium goose down insulation. The mattress, blanket and pillow are all separately inflated by means of built-in manual inflation devices called inflator sacks. This means that the 4” thick mattress is always inflated, while the blanket thickness can be varied according to the outside temperature. Finally, the orthopedically designed pillow can be set to the ideal firmness.
“I have tried a number of different air mattresses and pads, and have never found one that was truly comfortable. I sleep on my side, and usually would wake up with sore hips from rolling over. A few years ago I broke my femur in a bicycle fall, and though it has healed, my right hip is still a bit sore, and sleeping on my old, conventional air mattress really left me sore. The COCOON 4 has solved all that. It’s as comfortable as our king-sized mattress at home.”

C.M.K., Arlington, TX

“I am writing this from inside my new COCOON 4. I’ve been in for a week and I don’t want to get out. I think I have gone back to the womb. All kidding aside, your invention is nothing less than incredible. I have never been more comfortable sleeping before. Not only am I getting rid of my 2 sleeping bags, 2 pads & 2 tents, but my mattress and futon is going too.”

J.A.L., New Paltz, NY

“I would like to compliment you on the design and execution of your COCOON 4 Sleeping System. I have 15 years of camping experience, and have slept in several sleeping bags. However, yours is the most comfortable that I have ever experienced. The idea of combining an air-type mattress with the goosedown so that it does not become compressed was engenius (sic). The ability to adjust the thickness of the “blanket” or top of the sleeping bag according to the temperature is also one of its most desirable features. I especially like the raised toe. This allows much more comfort for the feet, and also provides a space to place your clothes so that they are warm in the morning.”

T.J.S., M.D. EVANSVILLE, IN


Notice the difference in the blanket thickness.
The upper bag is set for extreme cold, while the lower one is set for mild weather.

“In testing the COCOON 4, I’ve found it to be comfortable and durable. It’s so roomy, you can easily dress inside, and you can regulate the blanket for total comfort control, regardless of temperature. The COCOON 4 may be the ultimate for foul weather camping.”

DWIGHT SCHUH
BOWS & ARROWS EDITOR
SPORTS AFIELD MAGAZINE

IMPERMEABLE
Since the COCOON 4 Sleeping Bag is made from nylon which has been triple-coated with urethane (in order to hold air pressure), it is also completely waterproof. This means that the premium goose down insulation never gets moist or wet. Goose down is the best insulator for sleeping bags, so long as it is kept completely dry, because it is the lightest and most compressible. Synthetics were developed to provide some warmth even when wet, but at the cost of weight and bulk.
“Forget everything you’ve ever heard about or seen in sleeping bags. There is nothing out there like the COCOON 4. The COCOON 4 has an inflatable, down-filled air mattress and an adjustable down-filled “blanket”. It is adjustable by air pressure. In warmer weather, the blanket lays flat. In increasingly cold temperatures, more and more air is pumped into the blanket, increasing its loft. There is also a hoop-shaped “tent” that can be clipped over the head and upper one-third of the bag.

This is more than a sleeping bag; it is a sleeping shelter. The blanket and mattress both have a vapor barrier. This enables the outside to be waterproof. No moisture can get into the down from either external sources (e.g., a dripping snow cave, tent condensation, dew). If its windy, raining, or snowing, a breathable, windproof and waterproof “tent” with hoop poles clip over the sleeper.

This sleeping shelter proved very popular with friends and onlookers. The built-in air mattress makes it feel as if you are lying on a bed. Testers were astounded at its comfort.”

LARRY AMKRAUT,
TRILOGY MAGAZINE

“Before discovering the COCOON 4 Sleeping System, I had looked at many types of sleeping shelter. Any system that I looked at which would be warm, waterproof, and comfortable, was generally too bulky. The COCOON 4 met all of these requirements, all in one convenient package. Above all else, it is the most comfortable bag I ever slept in.”

B.G., GEORGETOWN, ON


The COCOON 4 is compact, lightweight and convenient to carry and store.
(Mug used for scale purposes only and is not included)

“The COCOON 4 has lived up to all the claims you made. After using it on my hunting trips I am totally amazed. Not only does it provide the greatest nights sleep, in South Dakota it is a life support system. We encounter great weather changes here and with the COCOON 4 we have them all covered.

This year on my mule deer hunt we had a rain storm that turned to snow and extreme cold. When I got back to my COCOON 4 there was an inch of ice on top of it. I removed the ice and got into my COCOON 4 and was totally warm in seconds. In the morning all my wet clothes were totally dried. The only excitement I had is when a porcupine tried to get in and left one quill in my bag which I removed in the morning and patched with the field repair kit.”

B.M., RAPID CITY, SD

COMFORTABLE
The human body gives off from 1-3 pints of water per night, even when one feels cold. In a traditional sleeping bag, this moisture is wicked away into the insulation, where it condenses and possibly freezes. As this happens, the bag looses its warmth. Since the COCOON 4 is made from air-holding fabric, it is also a vapor barrier, keeping water vapor next to the occupant and away from the down insulation. In 1975, the inventor of the COCOON 4 , Dr. Richard Malcolm discovered that the skin would reabsorb the moisture it gives off, so long as the person’s body temperature did not get too high, thereby causing profuse sweating and overpowering the absorption mechanism.
“One day, on the North shore of Lake Erie in Canada my son, Adam, left the zippers to my COCOON 4 open all day during a driving rain. I was piqued when I crawled into bed that evening into several cupfuls of water. I picked up the inflated COCOON 4 to drain it out — although I might as well not have: I got just as soaked in the rain as I would have been if I had crawled into the clammy bag. When I got into the bag it was indeed clammy — I was not encouraged. After undressing in the bag I wrung out my wet clothes and stuffed them into the bottom of the bag where there was plenty of room for them. WITHIN MINUTES the impermeable inner space had warmed to comfort level and, suddenly, I realized that it didn’t matter that I was still damp. (Since no evaporation takes place inside the COCOON 4, the moisture quickly reaches skin temperature, and is not felt.) With the integral down filled air mattress fully inflated, the down filled blanket fully deflated and the tent fly secured against the downpour I was quickly to drift asleep with the lullaby of the rain beating against the tent. The next morning dawned clear and cool and I was clearly SURPRISED to find that I was completely dry! Also, to my amazement, the soaked clothing I had stuffed into the bottom of the bag was only mildly damp.”

P.C.B.CORTLAND, NY

Since the COCOON 4 is completely waterproof, cleaning it is easy. It can be washed off with soapy water and a washcloth, and then rinsed. If one is looking to make it germ-free, it can be washed down with rubbing alcohol or scrubbed with a cleaning solution such as Virex TM and hosed down. This is ideal for those using COCOON 4’s in a rental program.
almost INDESTRUCTIBLE
The COCOON 4 is built tough. Every seam, seal, component and piece of hardware has been tested under conditions that no prudent owner would ever expose his/her COCOON 4 to. Nevertheless, some people had to confirm this for themselves.
“We recently read with interest your company’s propaganda, which stated that you had pulled a man in a COCOON 4 across a gravel parking lot with no noticeable damage. Being the skeptics that Alaskans tend to be, we decided to put one of our bags through a test of our own. The guidelines for the test were set late that evening over several bottles of Tundra brew.

The next morning we set up our newest COCOON 4. We then tied it behind a 64 hp Scat Hovercraft and inserted a not so willing volunteer. The bag was tied off 20 ft. behind the hovercraft so as to get the full effect of the 40 mph wind the fan generated. At 20 mph we crossed 100 yards of rough, marshy Tundra onto a pond about 300 yards wide. A short stop in the middle just to see if the bag and volunteer would float. Then once around the edge of the pond and back to the starting point.

Back at the starting point we were surprised to see that the bag was still inflated. The volunteer, who we thought would be completely soaked, emerged bathed only in the perspiration of fear. Upon close inspection, of the bag and tent, the only damage we could find was a 3 inch tear in the mosquito netting. We were amused to say the least. We had planned to send you a bag in need of a little warranty work, what we got was a bag that only needed to be washed off and put away.

Our compliments from the staff and volunteer for such a durable product.”

UPRIVER OUTFITTERS, AK


Combined weight of 1120 lbs jumping on an inflated COCOON 4 Mattress

“I purchased a COCOON 4 about four years ago. Since that time, I’ve used it an average of about 75 days a year in a variety of conditions. It is the ONLY bag I take when I go backcountry touring in the winter. I usually don’t even take a tent or tarp unless I expect the liquid snow that we so often get here in the Northwest. The bag is also my primary piece of gear when I go on whitewater river trips and sea-kayak trips. I’ve used it on self-supported kayak trips down class IV whitewater rivers like the Main Salmon at high water and the Selway, and I used it on a 28 day supported trip in the Grand Canyon. It has been with me as I toured almost the entire West Coast of Vancouver Is. and parts of the North Coast of B.C., and it kept me warm and dry in some terrific blows (50+ knot winds) that lasted for days. The bag is more comfortable than my waterbed at home. You truly have a very well designed product.”

P.W., PASCO, WA
REMARKABLE
The COCOON 4 is the only true 4-season sleeping bag in the world. It offers unparalleled comfort and safety under just about any conditions you are ever likely to encounter.
“I am a 63 year old, retired teacher with a lifetime of outdoor experience. Through the years I have seen many improvements and innovations in equipment, but none equal to your sleeping bag. I can state unequivocally that the bag is more comfortable than my own bed. It was used under all types of weather conditions from Southern California to Northern Canada; from the seashore to mountaintops with never an uncomfortable moment. I would highly recommend this bag to any serious outdoor enthusiast.”

J.K., EDMUNDS, WA

“I hate sleeping bags, almost as much as I hatebeing cold. As a New Englander in a family that loves the outdoors, this can be a serious problem!

When my husband suggested we test the COCOON 4 on a very cool, drizzly, fall evening, you can imagine my reaction! And none was more surprised than I the next morning when I couldn’t stop raving over the COCOON. Not only was I very comfortable, I was warm, dry, and slept like a baby.

I know I will never climb Mt. Kilimanjaro, nor is it likely that I will go trekking in Nepal. However, for all of those less adventurous souls who consider spending the night in a sleeping bag a form of torture, I wholeheartedly recommend the COCOON 4. I plan to spend many happy evenings underneath the stars!”

J.C.P., COHASSET, MA
“P.S. Our COCOON 4’s have been pressed into service for unexpected guests, our children’s numerous sleep-overs, even for rainy-day fun time.”

“This year’s Iditarod (1992) had the widest temperature range ever. Middle of the race was 52° below F. When I got to the coast (Bering Sea) it was 40° above F. & raining. At 30° below, I slept in the COCOON 4 with my two leaders (Terry and Rita)... There was ample room. At 52° below- in Ophir Checkpoint- I slept in my COCOON 4 without any dogs- 4½ hrs. of good rest.”

B.H., ALASKA

“Instead of testing the bag in cold conditions, I found myself in the most atypical hot weather seen in the Washington area in many years. I learned much about the use of the System in hot, damp and rainy conditions. It is the best sleeping system I have ever used, or even seen in 30 years of outdoor activities.”

M.B., SAXTONS RIVER, VT

“The COCOON 4 takes all the challenge out of setting up camp in bad weather... It takes all the challenge out of staying warm and comfortable... It is very difficult to get out of bed in the morning. Thanks for making adverse weather fun!”

C.B., KENNEWICK, WA

“Now for a sad story. R.S. bought a COCOON 4 about a year ago. Last month he had a heart attack and died (sad part). (Ironic part coming up), besides myself, there are three other people in town who have contacted his wife asking about the possibility of buying his sleeping bag. (A widow with all her teeth, a job, a house and a COCOON 4 WOW!!!)”

R.S., DILLINGHAM, AK

THE CANOPY
One of the hallmarks of good design is that all of the parts, each with its clearly defined functions, come together naturally into a perfectly functioning whole. Since the COCOON 4 Sleeping Bag is totally waterproof, it does not need a tent to protect it. This gave us the opportunity to design a Canopy over the head of the Sleeping Bag which would keep the bugs and other unwanted visitors out, and yet provide limitless fresh air.


The Canopy is attached by a zipper to the head-end of the Sleeping Bag, and is held up by a 4-piece carbon and glass impregnated, resin rod which is remarkably strong and flexible even at 60 below zero. The corners are stretched into tension by shock cords which attach to the Titanium ground pegs.
The no-seeum mesh provides a horizon to horizon view, and there is ample space to store light, gloves, reading material snacks and personal effects.


Not only have we done a lot of R & D to develop the complete System, but we pay a great deal of attention to detail when making them. For example, we use Teflon™ coated YKK™ coil zippers, since they won’t snag or freeze up, and our tests have shown that they are just as strong as the big-toothed variety in this application.

The Canopy has a built-in fly, which can either be rolled up and secured, or deployed so as to keep the rain or snow off of one’s face. This fly extends well beyond the mesh, permitting the easy circulation of fresh air. Side zippers permit portions of the fly to be opened and secured, allowing the sleeper a wide range of control over the ventilation.
Since all tents accumulate condensation in humid air, we have designed the Canopy to allow droplets to run down the inside, where they drip from the hem to the ground. The mesh provides a second line of protection, so that if a droplet should dislodge from the fly, it lands on the mesh, where it then trickles down the outside. As a result of these features, only a tiny portion of the moisture which falls inside a normal tent ever finds its way into the COCOON 4.


An ingenious use of zippers permits the user to enter and exit the COCOON 4 without having to remove the Canopy. The full length side zipper(s) of the sleeping bag can be opened making access quick and easy.
Inside the Cocoon4