Your baby will enjoy a more comfortable and contented feed. The wide breast shaped nipple promotes natural latch on similar to the breast, making it easy for your baby to combine breast and bottle feeding. Petals inside the nipple increase softness and flexibility without nipple collapse. Innovative twin valve designed to reduce colic and discomfort by venting air into the bottle and not baby’s tummy.bottle neck makes filling and cleaning easy. Only a few parts for quick and simple assembly. The Philips Avent Natural bottle is made of BPA free material (polypropylene).