Ideal option to get started with bottle feeding. The Air Free vent is designed to help your baby swallow less air by keeping the nipple full of milk during feeding. Reducing the amount of air your baby ingests helps with common feeding issues such as colic, gas & reflux. The nipple stays full even when the bottle is horizontal, so your baby can drink in an upright position. This can help reduce reflux, aid digestion, and make feeding time more comfortable for you and your little one. Air Free vent is easy to assemble and to clean quickly and thoroughly.