Herobility Double Anti-Colic Baby Bottles are designed to provide a comfortable feeding experience for infants. Developed by parents and approved by babies, these bottles feature a unique double anti-colic system that prevents air from being swallowed and reduces colic symptoms. The ergonomically shaped teat closes the corners of the baby's mouth, and the air valves prevent a vacuum from forming inside the bottle. Made from BPA-free materials, these bottles are safe and environmentally friendly. The breast-like shape of the teat is accepted by 97% of babies, making feeding time easier and more enjoyable. The bottles are easy to clean and sterilize, and come in a pack of four with different colors: White, Gray, Iron Blue, and Blue.