Anti-Colic vent system is clinically proven to reduce colic. Decreases spit-up, burping and gas Breast-like nipple shape encourages a proper latch Includes storage/travel caps to store and transport easily. Safe for use in dishwasher (top rack only), electric, microwave sterilizers and boiling water. BPA Free Your options have never been better with Dr. Brown's Natural Flow Anti-Colic Options+ Narrow Baby Bottle Newborn Gift Set. The anti-colic internal vent system is clinically proven to reduce colic. Dr. Brown's bottles provide a more comfortable feeding experience for baby by decreasing spit-up, burping and gas. This vacuum-free feeding is closest to breastfeeding and Dr. Brown's silicone nipples provide a consistent flow so baby can feed at their own pace. The breast-like nipple shape encourages a proper latch for a more natural bottle feeding experience and eases the transition from breast to bottle and back again. Dr. Brown's vent system is proven to help preserve bottle milk nutrients and aids in digestion for a better night's sleep.