With the Philips Avent Natural flow silicone nipple, you can adjust the flow to 4 different rates by simply turning the bottle. The nipple features an innovative petal design for natural latch on similar to the breast so it's easy combining breast and bottle-feeding. The teat has a twin valve designed to reduce colic and discomfort by venting air into the bottle and not baby’s tummy. Petals inside the nipple increase softness and flexibility without nipple collapse so your baby will enjoy a more comfortable and contented feed. Suitable for new born babies and older.