Comfortable Efficient Pumping Flange size is important for pumping Our flange inserts can reduce the 24mm shield nipple tunnel down to the Correct Sizenot for 27mm shield For Momcozy The flange inserts can be used with most 24mm ShieldsFlanges For example compatible with Momcozy S12 ProS9 ProS12S9 breast pump Note It does not fit with Momcozy M5 More Compatible You can use with 24mm breast Shields for TSRETEMedelaSpectraElvieWillowBellaabyMotif LunaAmeda MYAAinsirPhanpyLuliaNaNaLazyLuxladykidzioeulumapTeexinFisroaKISSBOBOGoldeepBIOBOOMumeasyNanawawaTOVVILD and others Safe for Both Babies and Moms It is made of 100 foodgrade silicone It is skinfriendly and BPAfree It is easy to clean and sterilizer and you can use it with confidence Convenient No hassle of testing nipple size and selection anymore Meanwhile It is necessary to change out your pump parts regularly