Making the switch from breast to bottle? NUK Simply Natural nipples are designed to make that transition smoother for both baby and mom. These slow-flow nipples (this pack has the 3-hole version) are shaped to mimic the natural fit and movement of breastfeeding. They're now even softer and more flexible, moving with your baby's mouth for a continuous, comfortable latch. The unique scoop-shaped cavity allows baby's tongue and jaw to move naturally, just like at the breast. Plus, they feature NUK's advanced 1-piece Anti-Colic Air System to help reduce gas, colic, and spit-up by venting air away from the milk. Made from high-quality, BPA-free silicone, they're safe and durable. Accepted by 96% of moms in studies! Remember, these nipples are designed specifically for use with NUK Simply Natural bottles. A trusted choice for a more natural feeding experience.