The HydraPak Contour hydration reservoir is designed to fit most backpacks thanks to a wide range of clips, hooks and loops. Hydrating is easy due to the lightweight, self-sealing Comet Bite Valve that can be opened and locked with one hand. The internal drying tab means the reservoir can be reversed for deep cleaning and complete drying. A great addition to a wide range of tramping, mountain biking and cycling adventures!