Purpose and key benefit Flange inserts resize a standard 24 mm flange tunnel to a smaller, more accurate fit (sizes 12 mm–22 mm). A correct fit reduces rubbing, prevents squishing of the nipple, improves comfort, and helps pumping work more efficiently — often increasing expressed milk output without added pain or soreness. Why you need this Many mothers experience nipple swelling, discomfort, or low output when the flange opening is too large. These soft silicone inserts create a snug, fit so the nipple moves without rubbing against the flange wall and reduces the risk of soreness or injury. Size and fit guidance Available in a range from 12 mm to 22 mm to match your individual anatomy. Choose the size where, during pumping, the nipple is centered in the tunnel and does not rub or feel squished. Observe nipple appearance during a session — it should move and not be compressed. Compatibility Compatible with most breast pumps that use a 24 mm shield/flange (NOT compatible with 27 mm shield/flange). Works with: Momcozy, TSRETE, Paruu, Spectra, Elvie, Medela, Kmaier, Motifluna, Amedamya, Freemie, Lansinoh, Phanpy, Zomee, Bellababy, Missaa, Cppslee, Ncvi. Specifically fits Momcozy models M9, M6, M5, S12 pro, S9 pro, V1 pro, V2 pro. Material and safety Made from foodgrade silicone, BPA, soft and odorless. Skinfriendly material designed to reduce irritation and increase comfort during pumping. Performance advantages Creates a snug seal and correct tunnel diameter to improve vacuum efficiency. Reduces nipple friction and soreness, lowering the chance of injury from an incorrect fit. A practical option for mothers concerned about low milk output or discomfort during pumping. Practical use scenarios Returningtowork pumping: Use the correct insert to get more efficient, comfortable sessions when time is limited. Mothers with smaller nipples: Reduce the 24 mm tunnel to a better match to avoid rubbing and soreness. Sensitive or sore nipples: Install an appropriately sized insert to protect the nipple and maintain milk expression without pain. Notes Select the insert size that allows the nipple to glide in the tunnel without contact against the flange walls. These inserts are designed to adapt a 24 mm flange; they will not fit 27 mm shields/flanges.