ANTI-COLIC BABY BOTTLE. Anti-Colic internal vent system is clinically proven to reduce colic. Decreases spit-up, burping and wind. CONSISTENT FLOW RATE. Vacuum-free feeding is closest to breastfeeding and Dr. Brown’s silicone teats provide a consistent flow so babies can feed at their own pace. PRESERVES NUTRIENTS. The anti-colic vent system is proven to help preserve bottle milk nutrients and aids in digestion for a better night’s sleep. WIDE-NECK BREASTFEEDING BOTTLE. The breast-like teat shape encourages a proper latch for a more natural bottle-feeding experience and eases the transition from breast to bottle and back again. BOTTLE GROWS WITH BABY. With three teat levels included, Slow Flow, Medium Flow and Medium-Fast Flow, bottle grows with baby! Dr. Brown’s Natural Flow Anti-Colic Options+ baby bottle works best with the internal vent system in place but can be removed as baby’s feeding develops – no need to introduce a different bottle.