1 bottle for feeding This is the perfect package to get you acquainted with bottle feeding. By holding the nipple full of milk while eating, the AirFree vent helps your baby swallow less air. Reducing your baby's air intake will help with common feeding problems like colic, gas, and reflux. Your baby should drink in an upright posture so the nipple remains filled even though the bottle is horizontal. This will help to relieve reflux, boost digestion, and make feeding time more enjoyable for both you and your infant. AirFree vents are simple to assemble and clean, and they dry easily and thoroughly.