With camping season well underway, it’s high time people upgraded their outdated gear. As someone who enjoys spending the night in a tent all year round, I’m always on the lookout for mats that can be used in the cold, which is why I was excited to try Rab’s Hypersphere Ultra 7.5 Down Sleep Mat.
This lightweight camping mat is different from other models in the sense that Hypersphere Ultra 7.5 doesn’t just rely on air columns to keep you warm; it also enlists a winter jacket staple ingredient to ensure you stay toasty no matter what the ground temperature might be.
Yes, the pad uses 800 fill power down to boost its warm retention capabilities without adding much (any) bulk. The pad weighs a were 610g (~21.5 ounces) and packs down small, albeit not as small as some two-season mats.
A small price to pay for such an incredibly warm pad, though, that can be used practically 12 months a year. In fact, the Rab Hypersphere Ultra 7.5 Down Sleep Mat is the warmest pad I've tried so far, and it’s quickly becoming my favourite. Should you get one? Let’s find out.
Rab Hypersphere Ultra 7.5 Down Sleep Mat review
Price and availability
The Rab Hypersphere Ultra 7.5 Down Sleep Mat was launched for the Spring-Summer 25 season and is available now at Rab UK and Rab US, with prices from £190/ $250 (~ AU$ 386.93). It comes in three versions: Regular, Regular Wide and Long Wide. I usually opt for long sleeping mats, but on this occasion, I went with the Regular size and it fit me just fine. The Hypersphere Ultra 7.5 comes in one colour, Marmalade.
Specifications
- Weight (regular): 610g / 21.5oz
- Dimensions (regular): 183 x 51 x 8cm/ 72 x 20 x 3.15 inches
- Packed size (regular): 24 x 14cm/ 9.4in x 5.5 inches
- R value: 7.5
Design and materials
Rab markets the Hypersphere Ultra 7.5 as the “ultimate sleep mat for moving fast in cold places, from high altitude mountaineering to arctic ultra running.” And what do these athletes need? Small pack size and exceptional warmth.
To achieve this, Rab combined what they know about down-filled jackets and inflatable mats, and voila! The Hypersphere Ultra 7.5 features 800FP down and a 20D recycled polyester shell and has an incredible R-value of 7.3.
The mat has a ‘hybrid’ rectangular shape with oversized outer chambers that help keep you centralised on the mat. Essentially, you roll back in the middle, even if you wiggle yourself off to the sides during the night.
The 20-inch width is plenty spacious and doesn’t taper towards the end of the pad, which makes it less likely you find yourself off it when turning. The Hypersphere Ultra 7.5 comes with a surprisingly handy pump sack and a two-way valve, enabling you to inflate and deflate the mat quickly.
The mat’s weight is kept to a minimum, the regular weighing only 610g (~21.5oz) – quite lightweight for such a warm pad. The Vango Aotrom Thermo Platinum has more or less the same weight, but its R-value is only 4.2. The Rab’s pack size is considerably small, but the added down makes it a bit thicker than non-down-filled mats.
Performance and comfort
I was very pleased with the inflation process of the Hypersphere Ultra 7.5. Pump sacks aren’t always reliable, but the one included with the mat works perfectly. I had it permanently attached to the two-way valve and fanned air in before rolling the sack to move the air into the sleeping mat. It worked like a charm!
The only difference between inflating the mat is that you have to shake it to move the down around once it’s been inflated. According to the pictographs explaining the process, you have to let the mat rest for half an hour after shaking; maybe to let the down settle? Surely, the feathers would settle if you lay on the mat, too.
Deflation is incredibly quick, too. You only have to pop open the second valve, and the mat deflates instantly. To my delight, the Hypersphere Ultra 7.5 fits back in its stuff sacks perfectly – another feature that can be a bit hit-and-miss sometimes. The kit includes a few repair patches, in case you have an accident (not that kind of accident).
The Hypersphere Ultra 7.5 isn’t just convenient to set up, but it’s also super convenient to use. The mat has a rectangular shape, which isn’t great for weight but excellent for comfort.
That said, at 610g, the pad is far from being heavy. The pack size could be smaller, but I don’t expect a mountaineering sleeping mat to be smaller than a 10-pack of tissues. If anyone does, you might want to lower your expectations.
I slept like a baby on the Hypersphere Ultra 7.5. During testing, I used several lightweight sleeping bags, including the Sierra Designs Cloud 800 20 and the Patagonia Fitz Roy 30 F/-1 C, and even though it wasn’t freezing, the air and the ground were cold.
Well, I didn’t feel much of that, thanks to the Rab mat. That 8cm thickness, combined with the layer of down between you and the ground, takes the bite out of the cold and almost makes it feel like you’re sleeping on a proper camping bed. But without the bulk, of course.
It doesn’t make a lot of sound, thanks to the lack of crinkly internal materials used in some more insulated pads. That said, most sleeping bags use polyester fabric outers, which will rub against the also polyester shell of the Rab mat, making some noise in the process.
Verdict
The Rab Hypersphere Ultra 7.5 Down Sleep Mat delivers outstanding warmth without the usual bulk, making it ideal for cold-weather camping and fast-and-light missions alike. With 800 fill power down insulation, a plush 8cm thickness, and an R-value of 7.5, this mat offers top-tier comfort and cold protection in a lightweight, compact package.
Setup is quick, pack-down is easy, and the rectangular shape provides excellent sleep stability. It’s not the tiniest when packed, but the performance payoff is worth it. For year-round adventures in chilly conditions, this might just be the best ultralight insulated sleep mat out there.
Also consider
Vango Aotrom Thermo Platinum: The Aotrom Thermo Platinum is a solid choice for campers wanting reliable insulation at a more affordable price point. With an R-value of 4.2 and a 5cm thickness, it’s suitable for three-season use and packs down small enough to stash in a daypack. At around 610g, it’s heavier than the Rab mat but offers great value for budget-conscious adventurers.
Therm-a-Rest NeoAir XLite NXT: Weighing just 370g and packing down to the size of a water bottle, the NeoAir XLite NXT is ideal for fastpackers and ultralight hikers. Its R-value of 4.5 makes it capable of handling chilly nights, and the 7.6cm thickness offers impressive comfort for its weight. It’s not down-filled like the Rab, but the warmth-to-weight ratio is excellent for three-season missions.
