Dr Brown's Baby Bottle Options  Wide Mouth Green Stars 270ml is an anti-colic bottle with a patented ventilation system and proven effectiveness in reducing  colic, reflux, burping and gas. In addition, since the air that enters the bottle does not mix with the milk, it minimizes the oxidation of vitamins A, C and E and prevents a vacuum from forming in the bottle, reducing the risk of your baby suffering from otitis media. These are the bottles most recommended by pediatricians in the USA.