Dr Brown’s Natural Flow Wide-Neck Single Bottle has a unique patented two-piece vent system that helps make drinking more pleasant for babies. The design helps to reduce the occurrence of colic. This bottle channels air through the vent to the back of the bottle- which allows the milk to flow freely- whilst this design- along with the wide neck bottle- prevents air bubbles forming in milk- which can cause colic. The bottle is easy to clean- BPA-free- and dishwasher safe and can be used over and over again. Dr Brown’s Natural Flow Wide-Neck Single Bottle gives your baby healthy feeding through its innovative vent system- which prevents air getting through and reduces feeding problems like burping- wind and colic.