Store › Spectra Duckbill Valve Replacement Set Image 1 of 1 Spectra Duckbill Valve Replacement Set $27.12 For use with Spectra S1, S2, and 9 Plus breast pumps.Set of 2 Add To Cart Added! For use with Spectra S1, S2, and 9 Plus breast pumps.Set of 2 You Might Also Like Medela Symphony® Double Pumping System (model #67099) $59.99 Spectra Wearable Duckbill Valve & Backflow Protector $34.89 Spectra Breast Shield $27.12 Spectra 12V Power Adapter $43.22 Spectra Flange Kit $34.20