Natural Flow Preemie Silicone Nipples (3 Pack) by: Dr. Brown's. If your baby suffers from colic, spit-up, burping, or gas, these are all symptoms that your baby has ingested air bubbles while feeding from an ordinary bottle. The Dr. Brown's Natural Flow baby bottle is unlike any other baby bottle on the market. This bottle features a patented internal vent system that eliminates air bubbles and vacuum pressure found in other baby bottles. The Dr. Brown's Natural Flow baby bottle is the only baby bottle that features a patented internal vent system. This vent eliminates the air bubbles and vacuum effect to allow positive-pressure feeding with no air - similar to breast-feeding. These nipples are for feeding preemie babies. This nipple is available only for the standard Dr. Brown's Natural Flow baby bottle.

Please note that the nipple size is the same as the Level one nipple that comes with the standard bottle. The flow rate for the preemie nipple is slower so as to not fload the baby's mouth with milk.