This Classic Anti-Colic Teat is perfect for 1 month+ babies . The unique valve on the nipple flexes to your baby's feeding rhythm. Milk will only flow at the pace chosen by your baby to minimise overeating and spit-up, burping and gas. This product has been clinically proven to significantly reduce fussing by approximately 28 minutes a day as compared to the comparator bottle. This was especially true during the night-time. As your baby feeds, the unique valve on the nipple flexes to allow air into the bottle instead of your baby’s tummy.This Classic Anti-Colic Teat is perfect for 1 month+ babies . The unique valve on the nipple flexes to your baby's feeding rhythm. Milk will only flow at the pace chosen by your baby to minimise overeating and spit-up, burping and gas. This product has been clinically proven to significantly reduce fussing by approximately 28 minutes a day as compared to the comparator bottle. This was especially true during the night-time. As your baby feeds, the unique valve on the nipple flexes to allow air into the bottle instead of your baby’s tummy.