Sea to Summit are no strangers to ultralight camping gear and the Ultralight Insulated is their flagship sleeping mat within this category. Pack size is satisfyingly small at only 10x23cm which is about as small as a 'full length sleeping mat gets. The 183cm regular tips the scales at only 480g so it's also one of the lightest mats on the market.
Despite its small and light pack size the Ultralight Insulated manages an r value of 3.3 thanks to lightweight synthetic insulation and a heat reflective inner. The insulation in the mat keeps you protected from cold air rising from the ground, we've been warm enough on the Sea to Summit Insulated when nighttime temperatures are hovering just above zero.
The mat in general feels a little fragile, as is often the case with ultralight gear. We managed to puncture the mat on the first use, luckily a repair kit is provided so we were able to patch it up, but you definitely need to be extra careful and vigilant when choosing your camp spot.
The valve system has separate inflate and deflate and is easy to fine tune. You can inflate by blowing directly into the valve but this feels cumbersome, you're much better off buying the optional Air Stream Pump Sack which will set you back an additional £15 on top of the £110 for the mat itself - eek!
The Ultralight Insulated is good to sleep on if you manage to find a level, even patch of ground. It gives comfortable support for both back and side sleepers with plenty of shoulder and elbow room. It's a slightly different story on lumpy ground as the air sprung cells have a habit of forming to the lumps and bumps rather than evening them out.
Overall, we could see why people would and do love the Sea to Summit Ultralight Insulated but ultimately personal preference relegates this one to the bottom of the gear pile for us.
