The Osprey Hydraulics 3-litre (100 oz.) reservoir is a great upgrade from your standard reservoir. The reservoir meets pharmaceutical biocompatibility specifications to assure taste and odor free hydration, and employs Osprey's durable anti-microbial film to prevent bacteria and mold. A welded back panel keeps water stable on your back. Hassle-free, ¾ turn widemouth lid offers quick fills, while flexible ¼" hose delivers fast water flow. BPA and PVC free.