The NUK Anti-Colic Professional Adapter Set is now also available for all other 300 ml NUK First Choice baby bottles. Because swallowing air while drinking is a major cause of typical colic symptoms such as bloating, abdominal cramps and constant screaming. To prevent babies from swallowing air while drinking, you can now easily equip your existing 300 ml NUK First Choice baby bottles with this adapter set. The secret lies in the Professional Ventilation System, which prevents air swallowing even more effectively. It consists of an innovative combination of air valve and air duct. The air valve ensures that the teat does not contract when drinking. So your baby can drink without weaning. The air duct directs the air from the valve directly to the bottom of the bottle – without air bubbles coming into contact with the formula. This prevents the milk formula from enriching with air. And less air in the food means less air in baby's tummy.