Product Description Simple, flexible, and ultra-durable, the Hydrapak® Elite™ Reservoir can turn any pack into a hydration machine. The narrower width is ideal for smaller packs and vests. The patented wide slide top opening allows for fast filling and a leak-proof seal. It is the only reservoir on the market that is fully reversible, which makes cleaning and drying a breeze. Featured in over 40 performance brands, it’s easy to see why this universal replacement reservoir is the top choice in hands-free hydration.