Philips Avent Nipples, Set of 2, are clinically proven to reduce colic and are designed to allow your baby to control the flow. Features of these Medium-Flow Nipples include allowing air into the bottle instead of in your baby's tummy, helping to reduce overeating and spit-up. Philips Avent Nipples are dishwasher safe for easy sterilization. These BPA-Free Nipples are for babies who are three months and older. The nipples have three holes for added comfort and ease of use. Using these Medium-Flow Nipples Set of 2 is comparable to breastfeeding your baby.