Bottles and nipple specially designed for small and large babies. 2oz for small animals and 4oz for larger animals. Bottle feeding allows animal to refuse formula when full. Nursing action develops facial muscles and stimulates the normal flow of saliva. Bottle is durable enough to stand up to repeated use. Marked with graduations to make monitoring food intake easier and to help prevent over or under feeding. Nipples are elongated and balloon styles for longer palates, wildlife and exotic species. Constructed of durable, flexible silicon that are readily acceptable. Cleaning brush sized for the bottle to make washing thorough and easy.