2x 17 mm One-Piece Breastshieldm Extra Small w/Valve, Membrane for Medela Breast Pumps (Pump in Style, Lactina, Symphony); Made by Maymom Various sizes to choose for pumping comfort Hygienic replacement kit for Medela Pump in Style, Symphony, Lactina, Swing Single pump Spare parts for traveling and less frequent cleaning Interchangeable with existing Medela parts Contains breastshield x 2, valve x 2, membrane x 4 Compatible with ALL models of Pump in Style,  Symphony, Lactina, Swing Single pump Interchangeable with OEM parts. Retail package - great gift for mother-to-be. Personalized breastshield sizing for more pumping comfort and efficiency 13 breastshield sizes to choose from BPA free BPA, DEHP free Compatible &amp; Interchangeable with OEM parts Compliant with FDA and EU regulations for food contacts. Same suction as OEM parts Steeper sloped valve leaves less residual milk after pumping. No seams for air leaking No dropped milk bottle clear nipple tunnel to see through Simple Wishes Simplicity Most home made hands free bra Medela Easy Expression