Gregory Mountain Products 3D Hydro 2L Reservoir Works like a reservoir and dries like a bottle. Thanks to it's soft molded 3D design, the 3D Hydro reservoir works like a reservoir and dries like a bottle. Add in the Speedclip attachment system, spine handle, integrated hanger, and drylock magnetic bite valve and you have a one-of-kind solution. - Drylock magnetic bite valve attachment system - 3D design positions the water flat against your back for optimal stability - QuickDry Hanger: A convenient option for storage or hang drying on or off the trail, integrated into the reservoir itself