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.