Dr Brown's Preemie Flow Level 1 Wide-Neck Silicone Nipple, 2-Pack Wn0201-Intlx WIDE-NECK PREEMIE NIPPLE. Dr. Brown’s Slowest Flow Nipple offers a very slow flow for babies who are premature or with feeding difficulties. ANTI-COLIC BABY BOTTLE WITH NIPPLE. Preemie Flow 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 Preemie 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 Preemie Flow 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 Options+ wide-neck bottles. DISHWASHER SAFE. Safe for use in dishwasher (top rack only), electric and microwave sterilizers or boiling water. BPA Free.