Commercial Bargains 20 Automatic Water Nipple Drinker Feeders Rabbit Bunny Guinea Pig Ferret Mice Ideal for Rabbits, Ferrets, Chinchilla and other small animals Manufacturer recommends 3 small mammals per nipple. Does not require a drip cup. Recommended for a Gravity Feed System. For use with a hose connected with the provided Tees. Built-In Cage Clip On The Side