Philips AVENT NEW Natural Nipples are designed to help babies feed from both the breast and the bottle. The nipple's wide shape is similar to the shape of a breast, and its soft, rounded nipple encourages the same peristaltic movements used to breastfeed. Twin anti-colic valves keep air in the bottle and out of babies' tummies, making feeding more comfortable, thereby reducing colic. The nipples are made of soft, durable silicone and have a unique petal design that prevents nipple collapse while your baby feeds.