Replacement valves compatible with Momcozy S9/S10/S12 wearable breatpumps, Spectra Caracup, FEISIKE Cup 2011 Version, TSRETE pump; not for Freemie open system. Not original momcozy pump parts, not original momcozy duckbill valve For replacement valves for Elvie Stride Pump, buy it from Maymom: ASIN B0BBVKM4X7. Built to last. Maymom offers 3-month replacement warranty on this valve. Contact seller for replacement. Also, some batches of wearable pump valve base (or linker) is smaller than the other, this valve might not fit. Contact the seller for refund in this case. Duckbill internal diameter is 18.5 mm, and it can fit many wearable breastpump with silicone cup on the market having the 'linker' of 19-20 mm. Made from BPA free material (silicone). Worn or torn valves may contribute to decreased suction and/or milk backing up in tubing. Replace them when needed. Comply with EU and USA FDA regulations for materials that contact food. Tested by independent labs for quality and safety. All items packaged in retail pack, sealed by manufacturer Maymom. Can be cleaned with boiling water or water steam. Maymom duckbill valve compatible with Momcozy wearable pump models S9/S12, compatible with Elvie stride wearable pump, compatible with spectra Cara cup, FEISIKE Cup 2011 Version, TSRETE