MompMuir 15mm Flange Inserts Compatible with Momcozy S9/S10/S12/M5/M6/M9, for eufy, for Spectra S1/S2, for Medela, for Elvie, for Elvie Stride, Compatible with Lansinoh, for Freemie, for Amada MYA, for Bellababy, for TSRETE, for FEISIKE, for Rainyb. It will reduce the 24-25mm breast shields nipple tunnel down to 15mm. 2pcs each pack. The 15mm insert Suitable for nipple diameter 10-12mm(before a pumping session), or measure the circumference of nipple base about 31.40-37.68mm(before a pumping session). More different sizes are available, 15, 16, 17, 18, 19, 20, 21, 22mm. Soft silicone makes pumping more comfortable, and correct flange sizes make pumping more efficient. Second Generation Improved Flange Inserts: two levels taper design for milk flow without blocking, do not reduce the suction of the original pump. BPA and DEHP Free. SAME SUCTION AS ORIGINAL PUMP PARTS. EASY TO INSTALL & REMOVE. Boiling water safe, Steam safe, Dishwasher toprack safe. Food-safe, seamless design. We've been there and hence this nursing essentials gift set. Tested to ensure zero Chemical leaching, no BPA, leads, or Phthalates. Made up of 2 inserts. This product has a variety of models, which can change the size of the "breast milk channel" on the cover of the breast pump, so as to be suitable for mothers with different nipple sizes, help to improve the breast feeding efficiency and increase the pumping capacity, and make mothers more comfortable in the process of breast feeding.