Dr.brown Narrow-Neck Options+ Bottle, 120ml 1pack dr brown's bottles have a unique valve that removes air bubbles and vacuum in the liquid to help prevent stomach discomfort like colic, in the baby. the baby can suck at his own pace, and the valve makes the dummy not collapse. When the child gets bigger, you can remove the valve and use the bottle as a "regular" baby bottle. The new improved model option+ wide neck has a silicone teat that mimics the mother's own breast in a natural way. perfect for changing from chest to bottle and back again. . Prevents the most well-known causes of stomach disorders, type colic. . reduces the risk of middle ear discomfort. the patented internal air valve ensures that no air or vacuum develops in the liquid. . control tested for over 450,000 meals . more pleasant for the baby because it can suck at his own pace. the patented valve ensures that the dummy does not collapse, so that the meal can be enjoyed without interruption.