Exped SIM Lite 3.8

The Exped SIM Lite 3.8 is a lighter take on the self-inflating SIM mat, keeping the same 3.8 cm foam thickness but with a lower ASTM R-value of 3.4 and a weight of 750 g — 110 g less than the standard SIM 3.8. The saving likely comes from a lighter foam density and construction, which shifts the mat toward 3-season use rather than shoulder-season cold. The top fabric is 75D recycled polyester with a TPU laminate, honeycomb embossing, Oeko-Tex 100 certification, and a DWR finish to resist moisture pickup. It has two flat, low-profile valves, comes in Regular size (183 × 50 cm), and packs down to 26 × 16 cm — slightly smaller than the full SIM 3.8. A stuff sack and repair kit are included, backed by a 5-year warranty. At 750 g and roughly 221 g per unit of R-value, this is a compromise between the comfort of self-inflating foam and lower pack weight — a reasonable pick for summer and early-autumn multi-day treks where less insulation is an acceptable trade.