The Tommee Tippee Closer to Nature Advanced Anti-Colic Teats are designed to mimic the natural shape of the breast, promoting easy latch-on and comfortable feeding for your baby. The unique anti-colic valve helps reduce colic and discomfort, while the slow-flow teat is perfect for newborns. The teats are made of BPA-free silicone and are compatible with Closer to Nature bottles.