Nathan Vapor Wrap 2L Hydration Pack Our Vapor Wrap 2L has enough storage and pack capabilities to use in the North Face Ultra-Trail Du Mont-Blanc race which is one of the most noteworthy ultra races in the world Ergo-Response System keeps water and gear close to the body for maximum no-bounce comfort Secret internal pocket holds ice pack for added body cooling Strategically placed Shock Cords with one-pull tension lock offer customizable trekking pole configurations Intelligently placed bottle pockets will not interfere with arm swing