Dr. Brown's Ultra-Preemie Narrow Nipple is a trusted neonatal nipple for premature babies and babies with feeding problems. Used in hospitals and Neonatal Intensive Care Units (NICU) across the country, the Ultra-Preemie nipple is designed to help babies who experience difficulty with faster-flow nipples. This extra slow flow nipple offers a very small amount of liquid to help your little one develop feeding skills to breast or bottle feed full time. The Ultra-Preemie Nipple, together with Dr. Brown's 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 Ultra-Preemie 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 Ultra-Preemie 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 Ultra-Preemie Nipple fits all Dr. Brown's Narrow bottles. Safe for use in dishwasher (top rack only), electric and microwave sterilizers, or boiling water. BPA free. Always use vent system with Ultra-Preemie Flow Nipples. Important: Consult your health care provider before using the Dr. Brown's Ultra-Preemie Nipples to confirm it is recommended for your child's feeding challenge.