Sea to Summit Women's UltraLight Insulated Air Sleeping Mat

The Sea to Summit Women's UltraLight Insulated Air pad trims weight from the Ether Light XT design down to 480 g in Regular size (168 × 55 cm) by reducing thickness to 5.1 cm, while keeping the same R-value of 3.5 and Air Sprung Cell baffle construction. That's about 137 g per unit of R-value — one of the best warmth-to-weight ratios in this women-specific lineup — achieved through Thermolite fill with an Exkin Platinum reflective lamination rather than a thicker air chamber. The trade-off for the lower profile is less cushioning between hiker and ground compared with the 10 cm Ether Light XT, which side sleepers on uneven terrain will notice more than back sleepers. The 30D/40D nylon fabric uses a liquid-extruded TPU lamination on both faces for puncture resistance, and the wider hip and knee zone targets side-sleeping comfort. It ships with an Airstream pump sack and repair kit but skips the stuff sack, and Sea to Summit rates it as quiet. A solid choice for three-season backpackers and thru-hikers prioritizing low pack weight over maximum cushioning.