
ltbgtDr. Brown's Natural Flow BPA Free 4 oz. Bottle 6 packltbgtltbrgtltbrgtDr. Brown's bottles features the Patented Internal Vent System which eliminates the negative pressure and excess air ingestion. This system is the only vent that eliminates the vacuum and the air bubbles found in most baby bottles. It allows air to enter through the nipple collar without being incorporated into the breastmilk or formula. ltbrgtltbrgtThe air is then channeled through the internal vent system to the area above the breastmilk or formula. Babies feed more comfortably because the vent allows them to nurse without fighting the negative effects of a vacuum or discomfort of ingesting air bubbles. This helps to reduce colic, spit up, burping and gas. ltbrgtltbrgtThe breastmilk or formula flows freely through the nipple as the air is channeled to the top of the bottle. This positive pressure eliminates nipple collapse, and can help reduce build up of fluid in baby's ear. The vent system is also proven to minimize oxidation of breastmilk and formula, to help maintain essential nutrients. ltbrgt