Spectra Pump Compatibility：compatible for Spectra S1, S2, 9 Plus, and Synergy Gold breast pumps, Complete Replacement Kit content:4 Flanges (19mm), 4 Duckbill Valves, 4 Backflow Protectors, 4 Tubes, and 4 Bottles,easy use whether you’re a first-time mom or a seasoned pro Durable & Built Tough：Upgraded duckbills with small pull tab – super easy to handle and made for frequent use Find Your Ideal Fit: We offer different size : 13mm 14mm 15mm 16mm 17mm 18mm 19mm 20mm 21mm 22mm 23mm 24mm 25mm 26mm 27mm 28mm 29mm 30mm 32mm to ensure a precise, comfortable fit. Reliable Performance：Designed to form with Spectra wide-neck bottles and milkflow bottles, this flange prevents milk leakage—eliminating mess. use at any hour, anywhere Compact & Travel-Ready Spectra Pump Parts：Lightweight and space-saving, these replacement pump parts are ideal for on-the-go mothers. Keep a set of Spectra pump parts in your diaper bag, office, or car—always-ready convenience for motherhood’s demands. Pump Parts 4PCS Replacement Kit for Spectra S1/S2/S9 Plus/Synergy Gold – Includes 19mm Flanges, Duckbill Valves, Backflow Protectors, Tubes & Bottles (Not Original Accessories)