The Philips Avent Anti-Colic Bottle with Slow Flow NIpple is designed to reduce most common feeding issues like colic, gas, and reflux. Unique AirFree vent keeps the nipple full of milk, not air, for easier upright feeding in a range of positions.Designed to reduce most common feeding issues including colic, gas, and reflux. Unique AirFree vent keeps the nipple full of milk, not air, as baby feeds in a range of positions for easier upright feeding. One-piece AirFree vent is easy to clean without any special tools. Bottle features a valve that decreases vacuum buildup to reduce the amount of air going into your baby's tummy. Bottle can be used with or without the AirFree vent. Comes with a slow flow (Stage 1) nipple. Nipples with different flow rates (sold separately) can be used with the bottle to suit baby's feeding needs. For babies 1 month and up. 100% polypropylene bottle/silicone nipple. Dishwasher safe. 9 fl. oz. capacity. Measures 2.76" diameter x 6.3" H. Imported.