Developed in Britain, award-winning Avent bottles more closely simulate the natural feeding process for happier, less colicky babies. The Avent bottle"s broad, soft silicone nipple mimics the shape and feel of the breast so Baby can suckle more naturally. Plus, a patented anti-vacuum valve allows air into the bottle as Baby feeds, so less air is swallowed than with conventional bottles. Wide neck design makes cleaning and filling easier too. Compatible for use with the Avent ISIS breast pump. In 9-oz. or 4-oz. sizes, each with newborn nipples. 3-pk. Imported.