Dr. Brown?s uniquely designed Wide-Neck Y-Cut Nipple works together with our patented internal vent system to help growing babies feed at their own pace with thickened milk and formula, or cereal. Each Y-Cut Nipple offers the same consistent flow, so both you and baby know exactly what to expect. Made of super-soft, high-grade silicone, the Y-Cut Nipple fits both Dr. Brown?s Natural Flow? Wide-Neck Bottles and Dr. Brown?s? Options? Wide-Neck Bottles. Easily clean this dishwasher (top rack) and sterilizer safe nipple. BPA free.