Bottles and nipples specially designed for small and large babies: 2 oz. for small animals and 4 oz. for larger animals. Bottle feeding allows animals to refuse formula when full. Nursing action develops facial muscles and stimulates the normal flow of saliva. Bottles: Durable enough to stand up to hard use. Marked with graduations to make monitoring food intake easier and to help prevent over or under-feeding. Nipples: Constructed of durable, flexible silicon that is readily acceptable and latex-free. 2oz