Why VentAire Advanced Bottles are better for baby: A clinical study confirms that babies using Playtex VentAire Advanced bottles had less gas, spit-up, colic and other discomforts than with other leading bottles. Here's Why: breakthrough Micro-Channel Vent technology. Unlike ordinary bottles (other bottles air vents through nipple, causing bubbles in liquid), VentAire Advanced keeps air at the back of the bottle as baby drinks, so virtually no air mixes with the milk and gets into baby's tummy. Reduces the negative effects of vacuum build-up, so baby controls the milk flow comfortably. Angled bottle design helps prevent ear infections. Promotes the semi-upright feeding position recommended by pediatricians to help prevent ear infections. Air vents through bottom vent, so air doesn't mix with liquid as baby drinks. Standard - original, slender shape bottle and nipple. Easy for baby to hold. Easy to clean. All parts top-rack dishwasher-safe. Removable top and bottom for easy cleaning. Leak-proof. Break-proof. Compatible with our line of Nursing Necessities breast pumps.