Dr Brown\'s Options+ Baby Bottles are convertible bottles that can be used with or without the vent system, preventing wind-related colic. Dr. Brown\'s Options range grows with the needs of your baby and offers health benefits whether your little one is experiencing feeding challenges or not. The unique design of the bottles internal vent system creates a 100% vacuum free environment, which is clinically proven to reduce wind-related colic. As your baby grows, you can remove the vent system and use the bottles conventional teat-vented system. The scalloped design of the teat allows air to vent through the bottle when not used with the internal vent system. Product Features Grows with your baby Easy to use Prevents wind-related colic Can be used from birth The Options plus teats are only for use on the Dr Brown\'s Options plus vented bottles.