Product Content: 21mm Flange (x2 Small Flange), Backflow Protector(x2), Tube(x2), Duckbill Valve (x2), Bottle with a Two-Piece Travel Cap (x2). All Products compatible with Spectra 9+, Spectra S1, Spectra S2 Breastpump. This kit does NOT include Dome Caps and Nipples. Maymom-made products. Not Original Spectra S1 Accessories. Not Original Spectra S2 Accessories. Not Original Spectra Pump Parts. All pump parts made by Maymom LLC. Maymom pump parts perform as well as OEM parts. Interchangeable and compatible with Spectra pump parts. Ideal Spectra replacement for Spectra Duckbill Valve (Spectra Valve), Spectra Backflow Protector, Spectra flange, Spectra Tubing, Wide-Neck Spectra Bottle. Maymom flange size available: 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 27mm, 28mm, 30mm, 32mm. The two-piece cap of Maymom bottle features rewritable surface top for labeling date or baby's name for daycare or daily storage use. Write with regular ball pen or dry erase marker. Erase with soapy water. US FDA registered medical device (No. D192499), Health Canada License (No.26003), Australian Health and Aged Care (ID 463470). Inspected by US FDA. Comply with FDA/EU regulations for plastic materials that contact food. Test reports are conducted by independent lab and available online for reference. Can be cleaned with boiling water, water steam or microwave-steam bags. Retail packed, sealed by the manufacturer - Maymom, not original Spectra parts. This product is made by Maymom to fit spectra S1/S2 pumps in addition to spectra 9 and spectra M pumps.