It helps air dry your bladder to prevent mold. Sure you could use a metal hanger so something else but that could damage your bladder or leave contaminants in it. Buy this as a kit and save money.

The biggest drawback of the soft CamelBak reservoirs is draining them dry. With Platypus reservoirs, you simply blow them up a bit by mouth and let them drain and dry. CamelBak's soft material won't allow that. Now, this bit of twelve-dollar plastic does work as advertised, but rather than spend money on what probably cost eleven cents to manufacture in China, I use a twelve-ounce empty Coors can, although most other brands works just as well. Simply slip the empty can through the filler hole, hang the entire unit upside down to drain and dry and you're done. If you're the fastidious type, you may want to rearrange the can once or twice to drain any water that was trapped between Coors and CamelBak. On sale, Coors costs about $3.99 for a sixer. That's six dry-outs or, if you're like me, one dry-out and a nice buzz. Figure out what your priorities are.

Its overpriced, but does what its suppose to do. I don't get any mold using this. I just wish my camelbak didn't make the water taste like plastic. I've tried everything. I'm going back to bottles.

I agree with oregonguy, not so much about the beer can (maybe a margarita glass!), but about the fact that there are better options than this. instructions don't exist about exactly how to position the inflater piece to keep the inner bladder walls from contacting and holding moisture. the hanger is handy, though i'll probably combine my old method, also used by ripplespirit, of inserting the drinking tube inside the bladder along with this equipment.

This works well to dry out your bladder and keep it clean. You can always just stick the tube into the bladder to keep it open and hang it by the hook. This is definitely easier though.

If you are like me, and you are constantly cleaning you hydration reservoir, then this is a must! You just slide it in the opening, hang it to dry and come back to it later.