Review: First Ascent Aero 5.5 Lightweight Mattress

When packing my backpack for a multi-day hike, space has always been more of an issue for me than weight. I have plenty of lightweight gear, but some items — like a sleeping bag and mattress — still take up valuable space. I used to strap my old foam gaper pad to the outside of my pack, but I’ve been more protective of my self-inflating Therm-A-Rest. Though smaller, it still takes up a lot of room. That’s where the First Ascent Aero 5.5 mattress comes in. Rolled up, it’s about the size of a 500ml Coke bottle, and weighing in at 426g (advertised as 410g), it’s one of the lightest full-length, full-width inflatable mattresses on the market.

The First Ascent Aero 5.5 compared to my Therm-A-Rest Prolite Plus, when rolled up.

I recently hiked the Giant’s Cup Trail, where the second night’s hut doesn’t have any mattresses. The rest of the huts are fully equipped, so it felt unnecessary to carry a bulky mattress just for one night. The team at Scuttle kindly supplied me with the Aero 5.5 for review — and with its tiny pack size and light weight, it was a no-brainer to bring along for a comfortable night’s sleep.

Comfort

Several design elements contribute to the comfort of this mattress. The width allows you to lie on your back without your arms falling off the sides — a small but meaningful difference. The Aero 5.5’s advertised dimensions are 189 × 54 × 5.5cm, offering plenty of space compared to many ultralight models.

For the record, I’m 1.85m tall.

Its egg-crate design offers improved comfort over parallel channels, allowing your hips and shoulders to settle naturally and preventing that slippery “slide off the mat” feeling common with other inflatable designs.

Source: www.firstascent.co.za

The one drawback is that it doesn’t hold its shape when you lean on your elbows or knees — the air shifts and you press through to the ground. Not a dealbreaker, but worth noting.

Inflation

The Aero 5.5 uses a super low-profile Seal Tec valve positioned on the underside of the mattress to stay completely out of the way when sleeping.

Despite being non-self-inflating, it only takes about eight breaths to fully inflate. The Seal Tec valve allows easy airflow and seals securely, preventing air loss during inflation.

Insulation

With an R-value of 1.3, the Aero 5.5 isn’t designed for extremely cold conditions on its own. However, paired with a foam gaper pad, it offers good warmth and puncture protection — an excellent combo for 3-season hiking.

Weight

At 426g, the Aero 5.5 is impressively light. My gaper pad weighs 176g, giving a combined weight of 602g — still 242g lighter than my Therm-A-Rest Prolite Plus (844g). Considering it costs nearly half the price (R1099 at time of writing), it’s easy to see the appeal.

Conclusion

I always carry a foam pad as a backup (and a comfy camp seat), so the Aero 5.5’s low pack size and light weight make it an ideal addition to my setup. Combined with a gaper pad for insulation, it’s a solid, compact, and affordable option for multi-day hikes.

The mattress is available directly from First Ascent and most outdoor retailers.