Osprey's Hydraulics Reservoir by Hydrapak is ideal for large volume packs and long duration activities. The HydroStatic backerplate provides structure for easy loading into a full pack and maintains a flat profile. Thoughtful design makes filling, cleaning and most importantly staying hydrated on the trail easier than ever. All parts are BPA-free, phthalate-free, lead-free, guaranteed. All materials are certified food safe according to FDA and EU regulations.