Mazama Designs Windigo, Top Fill Hydration Bladder, Replacement Water Bladder With Insulated Hose Fits Most Hydration Pack Water Backpack Applications UPGRADE YOUR HYDRATION PACK: Mazama's replacement hydration bladder fits most popular hydration packs and backpacks from brands like Osprey, Camelbak, High Sierra and more. Available in 70oz/2L or 100oz/3L, check your bladder compartment size to determine which is your best choice. TASTE THE WATER: The Windigo water reservoir features a taste-free, USA-sourced bladder film. Taste your water, not plastic. No PVC or BPA. WIDE MOUTH BLADDER OPENING: Windigo opens wide for fill-up and clean-up and features a lock and go leak-free closure that positively seals every time. A mid-line quick connect lets you load and unload your reservoir while leaving the drink tube connected to your pack. A BETTER BITE VALVE: Our Windigo hydration bladder includes our proprietary high-flow bite valve with a one-hand push button shut off. Super magnets on the bite valve and magnet retainer ensure easy fluid access on the go. INSULATED DRINK TUBE: Windigo replacement bladder comes equipped with an insulated drink tube for cold weather protection.