Philips Avent variable flow 3 month + teat is designed for thicker liquids and is suitable for babies over 3 months old. It has 3 flow rates dependent on where the teat is positioned against baby's nose - slow, med and fast. This anti-colic teat has a built in anti-colic valve that is designed to keep air away from your baby's tummy to reduce colic and discomfort. As your baby feeds, the valve integrated into the teat flexes to allow air into the bottle to prevent vacuum build up and vents it towards the back of the bottle. It keeps air in the bottle and away from baby’s tummy to help reduce colic and discomfort. The teat shape allows secure latch and the ribbed texture helps prevents teat collapse for uninterrupted, comfortable feeding. Clinically proven to reduce colic and discomfort, babies fed with Philips Avent Anti-colic teats and bottles experienced 60% less fussing at night, than babies fed with a competitor’s anti-colic bottle. Ideal for thicker liquids for babies aged 3 months and older. Directions Anti-colic teat clinically proven to reduce colic and discomfort. The anti-colic valve flexes to allow air into the bottle and not into baby's tummy.