Product Specifications Brand Pigeon Material Silicone Product Description Nipple is of perfect shape and size to fit into the sucking fossa of baby Inner vertical lines strengthen the structure of nipples; making it collapse-resistant Textured surface allows baby to latch on easily and securely 100% silicone nipple; super soft and flexible, allows natural and smooth tongue movement Air Ventilation System (AVS™) reduces intake of gas, a potential cause of colic