Dr Brown´s Bottle Options Bocal Largo Verde Estrelas 270ml is an anti-colic bottle with a patented ventilation system and with proven effectiveness in reducing colic, reflux, belching and gas. Furthermore, 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 the formation of a vacuum in the bottle, reducing the risk of your baby suffering from otitis in the middle ear. . They are the bottles most recommended by pediatricians in the US