The Natural Response Nipple works with your baby's natural feeding rhythm, making it easy to combine breast feeding and bottle feeding. The nipple has a unique opening which only releases milk when the baby actively drinks. So when they pause to swallow and breathe, the milk pauses too so you can confidently avoid milk loss whether at home or on the go. The wide, soft and flexible nipple is designed to mimic the shape and feel of a breast, helping baby to latch on and feed comfortably. The Anti-colic valve is designed to keep air away from baby's tummy during feeding, to help reduce colic and discomfort. Every baby feeds differently, and develops at their own pace. We’ve designed a range of flow rates (0m+, 1m+, 3m+, 6m+ & 9m+), so you can find the perfect one for your baby and personalize your bottle. All of the Natural Response Nipples are made of soft silicone. A wide bottle neck makes filling and cleaning easy along with only a few parts for quick and simple assembly. The ergonomic bottle is easy to grip at any angle to give maximum comfort during feeding, easy for your hands and tiny hands to hold. The Philips Avent Natural bottles and nipples are made of BPA free* material. Includes 1 bottle. * 0% BPA, following EU regulation 10/2011 What to expect when introducing the Philips Avent Natural Response Nipple. It is totally natural for your baby to take 2-3 tries to get milk flowing from a new bottle. Unlike traditional bottles the Natural bottle is designed to only release milk when your baby is actively drinking, like what happens when babies breastfeed. We have 5 different nipple flow rates for the Natural bottle. When looking for the right nipple flow rate, age is a guide, but your baby's approach to drinking and the feeding cues they will show will help determine when to move to a higher or lower nipple flow rate.