Tommee Tippee Closer to Nature Thick Flow Teats are designed to mimic the natural feel of a mother's breast, providing a comfortable and familiar feeding experience for your baby. The unique Easi-Vent valve helps reduce colic and discomfort, while the soft and flexible silicone material is gentle on baby's delicate gums and palate. These teats are BPA-free and designed for babies 6 months and older who need a faster flow rate.