The Reservoir 3.0 is a 3-liter water reservoir backpack perfectly designed to pair with your ALPS pack. The Ultravalve on the Reservoir 3-liter hydration bladder features a revolutionary 3-way articulating bit valve as well as a built in check valve that eliminates backwash and prevents air from entering the tube. It also has a feature that allows it to twist open for a no bite, full flow function. The anit-microbial IonPure treatment helps prevent bacteria and mold growth. The Reservoir 3l water reservoir backpack also features Dual Cap technology, one cap is large for cleaning while the other cap is small and perfect for filling with liquid. The quick connect device allows the drink tube to be disconnected from the reservoir without leaking for easy refill and cleaning. The insulated drink tube allows for use in extreme cold weather, and the drink tube clip rotates 360 degrees. This ALPS 3-liter hydration bladder features BPA and PVC free construction.