Dr. Brown?s Natural Flow Level 2 Nipple is the next step for babies 3 months+. Dr. Brown?s Level 2 Nipple, together with the Anti-Colic internal vent system, is clinically proven to reduce colic. Dr. Brown?s bottle and nipple 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 Medium Flow 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. The Level 2 Nipple and Anti-Colic vent system is proven to help preserve bottle milk nutrients and aid in digestion for a better night?s sleep. Made of super-soft, 100% silicone, the Level 2 Nipple fits all Dr. Brown?s narrow bottles. The suggested age range for the Level 2 Nipple is 3 months+, but baby?s preferred flow rate may vary. Safe for use in dishwasher (top rack