DESIGN & DETAILS: Advanced patterning removes all extraneous material to creates an ultralight, minimalist design that delivers comfort and support Chambers are placed only where padding is needed and eliminates them where they are not, allowing us to shed significant weight without sacrificing comfort Empty spaces between the chambers serve as expansion zones that allow your sleeping bag to fully loft beneath you, maximizing its thermal performance Streamlined size that is tapered to fit the body and fits inside or outside of your sleeping bag Features a customizable pressure valve with hand-pump for precise comfort Patch kit included for emergency repairs