The Dr Brown's Options+ Wide Neck Bottles Starter Kit contains all the bottles necessary to feed your child. The bottles use the Options venting system which is designed to reduce colic, burping and trapped air. It is also proven to help preserve levels of vitamins A, C and E in breast milk by reducing air bubble oxidation of milk. The unique internal vent system allows air to enter through the teat collar, preventing air bubbles or vacuum formation inside the bottle. The air is then channeled to the areas above the liquid. The absence of internal vacuum makes it easier for baby to feed comfortably., , It Includes: , 2x270ml & 1x150ml bottle , 2x L2 & L3 nipple , 2 cleaning brushes