Munchkin’s Latch bottle features a unique combination of ultra flexible nipple and one-way valve to help reduce gas and fussiness. Research shows that reducing gas and fussiness leads to better sleep for babies. This is why the Latch bottle is recommended by feeding and sleep experts. Experts also agree that a better latch eases the transition between breast and bottle, and back. That's why the ultra flexible nipple pumps and moves just like the breast, stretching back to your baby's soft palate for a correct latch. Set includes one BPA-free, easy-to-clean 4oz bottle with one ultra flexible silicone stage 1 (slow flow) nipple and one sealing disc.