TWIN PACK. Promotes natural feeding action. The AVENT Airflex Feeding Bottles uses an Airflex valve which works with baby's natural feeding action. Your baby controls milk flow, which can help reduce overeating and spit up.

As your baby feeds the built-in Airflex valve flexes to allow air into the bottle to prevent vacuum build-up. Air bubbles move away from the teat and into the bottle - not into baby's tummy.