Dr. Brown's Standard-Neck Level 2 Medium Flow Nipple(Pack of 2 Nipples)

Dr. Brown's bottle features a patented two-piece internal vent system that works unlike any other bottle design. The vent system fully vents our bottle for vacuum-free feeding, which we call positive-pressure flow, similar to breastfeeding. As the baby feeds, air is channeled from the nipple collar through the vent system, bypassing the breast milk or formula, to the back of the bottle. Air never mixes with the breast milk or formula which minimizes oxidation and helps preserve essential nutrients like vitamins C, A and E.