Pack of Anti-Colic bottles with PP wide neck, 2x150 ml, Dr Browns It works best using the internal ventilation system clinically proven to reduce colic, belching, expectorate and gazelle proven to preserve vitamins in milk vacuum-free feeding - aids digestion for restful sleep natural flow, supports breastfeeding It can also be used without the internal ventilation system - no need for a different bottle Includes: 2 PP bottles, wide neck 150 ml, 2 silicone teats level 1 (0-3 months), 2 internal ventilation systems consisting of 2 parts each, brush to clean the internal system, instructions. BPA Free