<p>This product is made by Maymom to fit spectras S1/S2 pumps. It is known that using the correct size of flange (breastshield) in breastpumping is the most important factor in achieving comfort and efficiency. Every mother was created differently. One or two sizes cant fit all. This is why Maymom develops more than 12 sizes of flanges spanning from 13 mm up to 36 mm to fit the average mothers and those mothers who need special sizes (e.g. 13, 15, 17, 36 mm). Measure your nipple diameter first, and then use the size selector of this listing to choose the size that is 1-2 mm larger than your nipple diameter AFTER a pumping session.<br><br>- Compatible and interchangeable with Spectra S2, Spectra S1, Spectra 9 Plus parts<br>- Same suction as OEM parts<br>- Fit snug with Spectra pump parts<br>- Easy to install, remove and clean<br>- FDA and EU compliance for food contacts</p> <p>Store in a cool dry area</p> <p>Taiwan</p>