Sea To Summit Ultralight Insulated

The Sea To Summit Ultralight Insulated is a three-season inflatable sleeping pad built around Air Sprung Cell construction — dozens of independent air cells replace the usual long horizontal tubes, letting the surface flex to the sleeper's shape and cutting lateral air movement that would otherwise carry heat away. Insulation comes from Thermolite synthetic fill backed by an Exkin Platinum reflective layer, giving an R-value of 3.1 under the ASTM F3340-18 standard — solid for spring-to-autumn trips, not enough for hard winter nights. In Regular size (183 × 55 cm, 5 cm thick) it weighs 480 g and packs down to 23 × 12.5 cm, smaller than a 1-litre bottle. The 30D top and 40D bottom fabrics use TPU lamination to keep weight down while resisting punctures from twigs and grit under the tent floor. A multi-function valve speeds up both inflation and controlled deflation. It suits hikers who want synthetic insulation — which still performs if it gets damp — without carrying the bulk of a dedicated winter pad.