Compatible and interchangeable with Spectra pump parts. Same suction power as OEM parts. Replace Spectra Flanges, Spectra Duckbill Valves, Spectra Backflow Protectors, Spectra Tubings, Spectra Bottles (Wide Mouth). DIFKING diaphragm does not fit the old version of spectra backflow protector; see photo for details. Multiple flange sizes available: 15mm,16mm,17mm, 18mm,19mm,20mm,21mm,22mm,23mm,24mm,25mm,26mm,27mm,28mm,29mm,30mm.