A liner that prevents moisture from your body from freezing inside your sleeping bag.Rab says:Ultralight sleeping bag liner to prevent moisture from the body getting in to down sleeping bags in extreme cold conditions.Our VerdictThe Hooded Vapour Barrier Liner goes inside your sleeping bag; it’s used in sub-zero temperatures and stops sweat and condensation from freezing inside your down sleeping bag, which would reduce the bag’s thermal efficacy and ability to loft.- Reviewed by Ultralight Outdoor GearFeaturesUltralight Silcoat nylonContoured hood with draw-string and cordlockIntegrated mesh stuff sackSpecificationsWeight: 158g (including stuff sack which is attached)Length: 225cm / 90inchChest Girth: 165cm / 66inchHip Girth: 150cm / 60inchFoot Girth: 105cm / 42inchPacked Size: 8cm x 18cm / 3 x 7inchFabric Outer: Silcoat :,1500 HH,DWR 80/20,55g/m,30d/30d,100% sil-nylon with PU coatingHelp & advice:About RabRab Sustainability and Responsibility

A liner that prevents moisture from your body from freezing inside your sleeping bag.Rab says:Ultralight sleeping bag liner to prevent moisture from the body getting in to down sleeping bags in extreme cold conditions.