Overview With the Philips AVENT Classic+ nipple, your baby controls milk flow, which can help reduce over eating and spit-up.The unique valve flexes to allow air into the bottle, promoting healthy, active feeding and reducing fussing and colic Clinically proven to reduce colic and discomfort Trusted for 30 years 2 pieces 3m+ Variable flow Benefits Easy latch on due to the unique valve on the nipple Unique valve on the nipple flexes to your baby's feeding rhythm. Milk will only flow at the pace chosen by your baby to minimize overeating and spit-up, burping and gas Clinically proven to significantly reduce fussing Sleep and nutrition are vital to your baby's health and happiness. A randomised clinical trial was carried out to see whether infant baby bottle design affects "infant behavior". The Philips Avent Classic baby bottle was shown to significantly reduce fussing by approximately 28 minutes a day as compared to the comparator bottle (46 min vs 74 min, p=0.05) This was especially true during the night-time. Unique anti-colic system As your baby feeds, the unique valve on the nipple flexes to allow air into the bottle instead of your baby's tummy. BPA free nipple This nipple is made from silicone - a BPA-free material (Following EU directive 2011/8/EU) Different flow rate nipples available The Philips Avent Classic bottle offers different flow rates to keep up with your baby's growth. Remember that age indications are approximate as babies develop at different rates. All nipples are available in twin packs. Adjust the flow rate to baby's convenience With the variable flow nipple, you can adjust the flow rate according to liquid's thickness and suit baby's feeding rhythm perfectly.