AVENT NIPPLE CLASSIC ANTI-COLIC 3M+ ,Avent Anti-colic bottle nipple for 3+ months has a unique anti-colic valve that flexes to keep air in the bottle and out of your baby's tummy, a feature that reduces fussing and colic,The unique valve flexes to your baby's feeding rhythm so milk will flow at the pace chosen by your baby for more comfort. These soft, rounded Anti-colic bottle nipples are made of durable, dishwasher-safe silicone, which is flavorless and odorless,At two weeks of age, babies fed with the Avent bottle showed a trend to less colic than babies fed with a conventional bottle.