With its integrated Anti-colic valve, air is vented into the bottle and away from the babys tummy. The clinically proven* Anti-colic valve is designed to reduce colic and gas. Clinical studies have shown that the Philips Avent bottle reduces colic and fussing. Fussing is significantly reduced at night, as babies fed with Philips Avent Anti-colic bottles experienced 60 % less fussing than babies fed with a leading competitor’s vented bottle.* * At 2 weeks of age, babies fed with a Philips Avent bottle showed less colic, and significantly less fussing at night compared to babies fed with another leading bottle. Nipple design proven to prevent nipple collapse and associated air ingestion and feeding interruptions. The nipple shape allows secure latch, and the ribbed texture helps prevents collapse for uninterrupted, comfortable feeding. This Anti-colic bottle is designed to prevent leakage whilst feeding, for a truly enjoyable feeding experience. With its wide neck and fewer parts, this bottle is easier to assemble and to clean quickly and thoroughly. Philips Avent Anti-colic bottle is made of BPA free material (PP). Philips Avent Anti-colic nipples are available in different flow rates (0m+, 1m+, 3m+ & 6m+), to keep up with your baby’s growth. It's recommended to replace nipples every 3 months for hygiene reasons. Use Philips Avent Anti-colic bottles only with Philips Avent Anti-colic nipples. Full Compatibility with Philips Avent Anti-colic bottle with or without AirFree vent.