Compatible With the Most Pump :The breastmilk collection cup compatible with most electrical pumps that use the traditional flange and bottle collection method. Milk collection cups compatible with spectra s1/s2/9 plus/synergy gold,Medela,Bellababy, Lansinoh,NVCI,Baby Buddha, Zomee, Legendairy Milk, Phanpy, and Freemie, enhancing your freedom to choose the best pump for your needs.(Please verify compatibility with your pump model before purchasing.) Upgraded double-sealed flange : Equipped with 24mm Flange is an upgraded double-sealed flange increase the seal and grab every drop of milk for a better breast-pumping experience,keep your breast pump at the best performance level. More Efficiency, Anti-backflow : Our wearable breast pump milk collector set can effectively help you improve efficiency. Different from ordinary design, our duckbill valves is designed on the side,anti-overflow design features on duckbill valve makes milk only goes up, clean and pollution-free. Food grade material :Made of soft food-grade silicone,they are easy to removable and clean.It is BPA-free and ensures the highest level of safety for your baby. Don't have need to sterilize it every time, you can just wash it with warm water after use, and air dry these parts on a clean and unused towel, paper towel or cloth.