Badly designed, and unfit for purpose.
Bought this bottle as my hamster lives in a glass terrarium and not in a cage, along with the wooden stand that you can get separately. But it's hopeless. Realised no water was coming out after 2 days. The spout is too narrow, and has a kink in it, trapping air inside, and my hamster was going berserk trying to drink with no water coming through. Loosening the cap slightly to break vacuum caused the opposite problem, with it dripping constantly from the spout and soaking the bottom of the cage.