FITS VESTS & PACKS: A perfect fit for most standard hydration vests and packs. Universal hanger is compatible with clips, hooks & loops in a wide range of packs. GRAB TAB: Light and flexible grab tab makes it easy to pull in and out of packs. WIDE FILL OPENING: Slide-Seal top opens extra wide, making it easier to fill and add ice. HIGH FLOW VALVE: Lightweight, self-sealing Comet bite valve can be opened & locked with one hand. 100% BPA FREE & EASY TO CLEAN: Reverse the reservoir for deep cleaning and complete drying.