- These breast pump accessories are only suitable for 24mm Shields/Flanges and cannot be used with other sizes of Shields/Flanges. Using coconut oil or nipple butter can reduce friction and make them easier to use. - Compatible with Momcozy S12 pro, S9 pro, S9, S10, S12 Wearable Breast Pump, and suitable for brands including Momcozy, TSRETE, Luxlady, HAUTURE, eulumap, CPPSLEE, Cupood, Fisroa, Goldeep, Zybeauty, PADRAM, HAHOME, Kompoll, OMFMF, Paruu, LRKHFFD, Mumeasy. - This replacement part is also applicable to most other brands of 24-25mm (Freemie) models, and is compatible with MISSAA hands-free breastpump. - The size of your flange insert is important for comfort and efficient pumping. Some users may experience nipple swelling during pumping, so observe the nipple during use. The flange insert should be replaced every 1 to 2 months. Please choose the right size. - Use scenario 1: You are upgrading from a different brand to a 24mm shield setup to improve fit and comfort across a range of pumps at home or on the go. - Use scenario 2: You experience nipple swelling or discomfort during pumping; select the correct flange size and consider a light lubricant to reduce friction. - Use scenario 3: You rotate between multiple pumps (Freemie 24-25mm or MISSAA hands-free models) and need a common, compatible insert for consistent comfort and performance.