So light you might forget you brought it, the HydraPak UltraFlask 500 fits snugly in most hydration vest pockets and shrinks as you drink to minimize sloshing.

• Soft material conforms to any pocket, in a size that's ideal for hydration vests, belts or pack pockets
•  Large 42mm opening lets you fill the UltraFlask easily with ice and drink mixes
•  Cap with adjustable drink tube and removable bite valve allows easy sipping
•  Bite valve can be mounted directly to cap, so you can use the flask with or without the drink tube
•  Can be frozen or filled with hot water (max temp 140°F)
•  Soft plastic is 100% free of BPA and PVC