Dr Brown's Options 270ml/5oz four pack comes with a level 1 teat & vent cleaning brush. The same trusted bottle, with added benefits, the new Dr Brown's Options is the first convertible bottle that can be used with or without the green vent system. The unique internal green vent system continues to create 100% vacuum free feeding, which is clinically proven to help reduce wind related colic. This is what makes 9 out of 10 Healthcare Professionals recommend Dr Brown's for the relief of wind related colic. The new Dr Brown's scalloped designed teat allows air to vent through bottle when green vent system is not used for when baby's feeding is developed or parents just want the convenience of a teat vented bottle.