The Evenflo Feeding Vented + Standard Neck Nipple is 100% silicone and features an integrated 1-piece venting system to help reduce the potential for colic, reflux, gas, and fussiness. The nipple has a gradual transition between nipple length and base to allow your baby to maintain their latch. The Vented + Standard Neck Nipple can be easily assembled and disassembled from an Evenflo Feeding Vented + Angled Bottle, for a quick, thorough cleaning between feedings. The dishwasher safe nipple (top rack only) is available in three flows: Slow, Medium, and Fast. The nipple is 100% free of BPA, polycarbonates, PVC and phthalates, and is also made of FDA-approved food grade material.