CONTENT: Membrane x2, Duckbill x2; Replacement parts Compatible with Momcozy S9/S10/S12 wearable pump; FEISIKE CUP and many other wearable pump. Not original Momcozy duckbill valve and silicone diaphragm. Built to last. Maymom offers 3-month replacement warranty on this valve. Contact seller for replacement. Worn or torn valves may contribute to decreased suction and/or milk backing up in tubing Made from BPA free material (silicone). Also compatible with many wearable pump on the market. See the dimensions (photos) of the products to determine compatibility Maymom pump parts compatible with Momcozy S9/S10/S12 and many other wearable breastpump on the market.