The large breast-shaped nipple facilitates a natural latch on, similar to breast feeding, making it easier for your baby to mix breast and bottle feeding. Petals within the nipple soften and stretch the nipple without causing it to collapse. Your kid will eat in a more relaxed and contented manner. By venting air into the bottle rather than the baby's stomach, this revolutionary twin valve eliminates colic and pain. This nipple is made of silicone, which is BPA-free (per EU directive 2011/8/EU).