Created by a physician, Dr. Brown"s bottles feature a patented internal vent system that eliminates the vacuum and air bubbles to help reduce colic, spit-up, burping and gas. The positive pressure design allows babies to feed comfortably, because the vent system eliminates the air bubbles and vacuum. Helps maintain vitamins C, A & E plus lipids. Easy to clean, dishwasher safe, BPA free. Includes 2 8oz Wide-Neck Pink Bottles, 2 Level One Silicone Nipples, 2 Two piece patented internal vents, 1 Cleaning Brush, Instructions.