Keep suction strong on your breast pump! The replacement Duckbill valve for Dr. Brown's custom flow double Electric Breast Pump, single electric Breast Pump, and manual breast pump has a unique design that maintains suction for longer. The 100% silicone Duckbill valve features an easy-pull tab that makes it quick and simple to pop the valve in and out. The tab prevents damage to the valve, which helps keep suction strong. Package comes with (2) Two replacement Duckbill valves for Dr. Brown's breast pumps. Replace every 3-6 months. Dishwasher (top rack) and sterilizer safe. It is recommended to use a small parts dishwasher bag. Bpa free.