Oasis All Weather Hamster Bottle contains a double ball point vacuum-valve. Ideal for hamsters, hedgehogs, sugar gliders, eats, mice and gerbils. Ideal for hamsters, gerbils, mice, rats, hedgehogs and similar pets Double ball point vacuum-valve for minimal dripping For indoor and outdoor use A durable 8 oz bottle designed with the angled cap and the smaller 5/16" diameter stainless steel drinking tube sized for the animals listed.