One of the best things you can do to keep a backpack hydration reservoir in good shape is to clean and dry it thoroughly after each use, and the Reservoir Dryer from CamelBak makes it easy. Use the hook to hang the reservoir upside-down from a tree branch, door knob, handlebars – practically anywhere. By hanging it upside-down, you'll encourage thorough drying and inhibit the growth of mold. The dryer is designed to be used with CamelBak Antidote reservoirs.