Critterville Water Bottles for small animals are made with durable, BPA free plastic and a stainless steel sip spout. This 10.14 oz. water bottle is the perfect size for guinea pigs or rats. Critterville Water Bottles are designed to fit ALL MidWest Homes for Pets' small animal cages, including Critterville Hamster Homes, Guinea Habitat guinea pig cages, Ferret Nation, Critter Nation, Wabbitat and Wabbitat Deluxe rabbit cages, and Critterville Small Animal Playpens. Each water bottle attaches to the cage with a user-friendly plastic screw, and also includes suction cups to use in a glass aquarium habitat. Keeping the bottle filled is simple with the easy fill lift-top cap - simply remove and fill!