Sized right for short trips - and their smaller packs and pockets - or as the base of a squeeze filter, the Stow (TM) holds its water, then, when empty, rolls up to stash in places other bottles won 't fit. It 's durable, flexible, has a flip-top cap cover to protect the high-flow and spill-proof nozzle, and an integrated bail handle that makes clipping and carrying easy. And, at a weight that 's 50% lighter than most hard bottles, carrying gets even easier. HydraPak Stow 500ML Flexible Water Bottle | Olive | Christy Sports