The Avent BPA Free Bottle is designed to fit your babys growing needs. Its anti-colic valve flexes to allow air into bottle to prevent vacuum build-up. Air bubbles move away from nipple and into bottle, not into babys tummy. Its two piece anti-colic system consists of the AVENT nipple and adapter ring which is naturally shaped to promote proper latch-on. Wide bottle shape for easy filling and cleaning Accurate feeding measurement markings on bottle Dome cap seals nipple for spill-proof mixing and transportation Dishwasher and microwave safe 6 9oz/125ml bottles Less fussing especially at night** Less colic*** BPA-Free. Bottle is made from Polypropylene (PP) a BPA-Free material