These ergonomically-designed Avent feeding bottles combine a specially contoured nipple with an innovative system that's clinically proven to reduce colic. Made of leak-proof, BPA-free plastic, each easy-grip bottle has a wide neck for easy filling and cleaning, and an adapter ring that vents air back into the bottle. The soft silicone nipple promotes a latch similar to breastfeeding and adjusts to the baby's unique feeding rhythm.