Superpet's Universal Water Bottle is the versatile bottle that works in every type of small animal home. The universal water bottle includes a free bottle hanger for hanging in any wire cage, as well as an adjustable o-ring for inserting into the top opening of Superpet Crittertrail homes, other modular systems, and Keep-a-Critter travel homes. Universal water bottle also fits directly into Superpet's water bottle holder for use in aquariums. For the Superpet water bottle with the refill reminder, click here....