maymom Similar to Maymom Pump Parts Work with Spectra S2 Spectra S1, 24mm Flange Valve Tube Bottle Backflow Protector, Not Original Spectra S2 Accessories Spectra Duckbill Valve Spectra Bottle Spectra Flange (24mm) is up for auction in Baby Products. The current bid is $1.00, 97% below the $34.99 MSRP, in Good Condition. This auction has ended — similar items appear in live auctions regularly.