The Avent Anti-Colic Baby Bottle Gift Set has a unique AirFree vent that is designed to draw air away from the nipple, keeping it full of milk. Even when the bottle is horizontal, the nipple stays full, so your baby can drink in an upright position. Feeding in an upright position can help reduce reflux, and aid in digestion. The Avent anti-colic bottles can be used with or without the AirFree vent. With its wide neck and fewer parts, the bottle is easier to assemble and to clean quickly and thoroughly. Set includes three 4-ounce anti-colic bottles with AirFree vent with Flow, one nipple, two 9-ounce anti-colic bottles with AirFree vent with Flow, two nipples, one bottle brush, one snack/formula dispenser, one snuggle pacifier holder, and one ultra soft pacifier (0-6 months).