Rab Exosphere 3.5 Self-Inflating Sleep Mat review: a brilliant three-season camping pad for comfort-first campers
Spoiler alert: I’m planning on getting a lot of blissful sleep at camp this summer
by Julia Clarke · T3T3 Verdict
⭐ ⭐ ⭐ ⭐
Rab may be a relative newcomer to sleeping pads, but the Exosphere 3.5 feels like a product from a brand that has been making them for years. Comfortable, stable and easy to live with, it delivers excellent sleep quality with minimal fuss. The foam construction does make it bulkier than ultralight alternatives, but for car camping and casual backpacking, it's an easy recommendation.
Reasons to buy
- Very comfortable and stable
- No annoying rustling
- Easy to inflate and deflate
Reasons to avoid
- Not the lightest or smallest
- Not for winter use
Founded in 1981, Rab has been making outdoor kit for exactly as long as I’ve been alive, but it only got into the sleeping pad game three years ago. I’ve loved their down jackets, waterproofs and winter gloves, so I was keen to get them out in the wild and finally managed to do so this spring.
The line of sleeping pads includes the Hypersphere Ultra (very warm) and the Ionosphere 5 (light and lofty), both of which we’ve rated highly at T3, but the Exosphere is a little less technical, more of a well-priced all-rounder. Don’t let that put you off, however, as it’s a great piece of kit.
The Exosphere 3.5 is the only self-inflating pad from Rab so far, which means it’s easy to set up and will be one of the most comfortable pads in its line.
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Conceived by Therm-a-Rest in the 1970s, self-inflating mats are a happy compromise between closed-cell and inflatable mats: more comfortable than the former and less flimsy and cheaper than the latter. They use foam for comfort and insulation, and will inflate most of the way on their own if you open the valve and go and do something for half an hour.
This three-season, rectangular-shaped pad gives you a little more real estate than a mummy-shaped design, and works for backpacking, but may be better for car camping. Can it rival a Therm-a-Rest? With the weather finally turning for the better here in the UK, I took it to the Isle of Mull to find out.
Rab Exosphere 3.5 Self Inflating Sleep Mat review
Price and availability
The Rab Exosphere 3.5 is available in Regular and Long/Wide sizes directly from Rab, with an MSRP of £110 for Regular (the size I tested) and £130 for Long/Wide.
The recommended retail price is on par with similar self-inflating mats from Therm-a-Rest, such as the ProLite, though spec-wise it’s closer to the more expensive Therm-a-Rest ProLite Apex. It’s substantially cheaper than almost all of Rab’s other sleeping pads (the Hypersphere Ultra 7.5 costs twice as much).
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Design and materials
The rectangular shape of this pad means there’s more of it at the bottom, and that means less of me ends up on the cold, hard ground. At the shoulders, it’s the same width as my Therm-a-Rest Prolite, though anyone with very broad shoulders should try the wider size for a nominal increase in price and packed size.
The real talking point in the design of this pad, however, is the use of XCore foam, which is apparently constructed in a honeycomb pattern to provide optimal support while reducing weight.
I imagine this functioning like the sole of a running shoe with large sections of foam cut out, yet still feeling springy. It’s 5cm thick when inflated, which I should point out is twice the thickness of the Therm-a-Rest ProLite and with a 3.5 R-value, it’s good for three-season use but not for winter camping.
Protecting that foam is a polyester shell that’s durable but feels quite nice against bare skin. In total, the pad has 14% recycled content, which is considerably less than the Rab Ionosphere 5, and its sustainability creds are slightly undercut by the fact that it’s manufactured in China, unlike many Therm-a-Rest pads, which are made in Ireland. But it is made without PFAS and uses a fluorocarbon-free DWR.
At 665g, it’s not the lightest pad out there, which is par for the course with self-inflating mats, and it packs down to 26cm x 17cm. Because sleeping pads like my Big Agnes Rapide SL have got so tiny in recent years, it looked huge to me at first, but after a few uses, I realised it’s just a standard-size mat that could work for backpacking, but is probably better for car camping.
Inflation process
There’s no fancy inflation sack here because, ostensibly anyway, you don’t need one. The Exosphere has a low-profile two-way valve that doesn’t stick out when it’s packed away and handy instructions sewn into the stuff sack.
I’m usually too impatient to actually let pads self-inflate, but in the name of journalism, I did open the valve all the way up and left it alone for 30 minutes. When I came back, it took just four puffs to fully inflate it.
On a recent car camp where I arrived at 10:30 p.m. and just needed to get some kip, I inflated it by mouth, which took somewhere between 15 to 20 breaths – not bad at all, though it is a little harder on the lungs than some pads.
To deflate, it’s a case of opening the valve and the air releases easily. I found it easy to roll it back up, though it can take a little bit of wrestling to get it back into its stuff sack. Fortunately, the sack has a stretchy opening and two stretchy bands, so it works well enough even when I pack it haphazardly.
Performance and comfort
I actually first used this pad to sleep in the back of my car, which is a much more lumpy affair than sleeping on the ground. But no amount of seatbelts or other automobile detritus was a match for this pad, which is plush enough to feel almost like my mattress at home.
It’s so stable that I can actually kneel on it in my tent without my knees touching the ground. I tend to sleep in many different shapes and positions, and when I’m on my side, my hip doesn’t get sore. It even works for sleeping on my front, which can’t be said for all pads.
It fits in my rather modest one-person backpacking tent, and its shape gives me more protection than a mummy-shaped pad. It’s free of annoying rustling and feels quite nice against my skin, unlike some pads that can be a bit scratchy or sweaty.
I’ve been testing it in spring conditions, and I’ve been warm enough. I wouldn’t use this for camping in the snow, but for milder winter conditions, which we often have in the UK, it would probably suffice.
Verdict
The Rab Exosphere 3.5 is a first-rate self-inflating sleeping pad, and it’s hard to see how the brand could improve on it next time unless they make it lighter and smaller or use more recycled materials.
It’s as comfortable a pad as you can find – supportive, stable, and pretty low maintenance overall. It’s tough enough to withstand being tossed around on your adventures and comes in at just the right price for its performance.
I’ll probably save it for car camping, but that’s only because I’m spoilt for choice with packable pads – if I were buying one pad for both car camping and backpacking, I’d strongly consider this one.