Dr. Brown’s Natural Flow Level 4 Nipple is the fastest flow for babies 9 months+. Dr. Brown’s Level 4 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 Fast 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 4 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 4 Nipple fits all Dr. Brown’s narrow bottles. The suggested age range for the Level 4 Nipple is 9 months+, but baby’s preferred flow rate may vary. Safe for use in dishwasher (top rack only), electric and microwave sterilizers or boiling water. BPA free. FAST FLOW NIPPLE FOR BABY. Dr. Brown’s Fast Flow Nipple is the fastest flow for babies 9m+. ANTI-COLIC BABY BOTTLE WITH NIPPLE. Level 4 Nipple, with Anti-Colic internal vent system, is clinically proven to reduce colic. Decreases spit-up, burping and gas and provides a more comfortable feeding experience for baby. CONSISTENT FLOW RATE. Vacuum-free feeding is closest to breastfeeding and Dr. Brown’s Fast Flow Nipples provide a consistent flow so babies can feed at their own pace. DEPENDABLE NIPPLE FLOW. Each nipple level provides clinical consistency within the flow rate, so baby’s feeding experience is constant and comfortable. BREASTFEEDING SILICONE NIPPLE. 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. PRESERVES NUTRIENTS. The Level 4 Nipple and Anti-Colic vent system is proven to help preserve bottle milk nutrients and aid in digestion for a better night’s sleep. SOFT 100% SILICONE. Silicone nipple fits all Dr. Brown’s narrow bottles. DISHWASHER SAFE. Safe for use in dishwasher (top rack only), electric and microwave sterilizers or boiling water. BPA Free.