The Spectra Breast Shield Set offers a larger 28 mm replacement flange for the one that came with your Spectra 9Plus, Spectra M1, Spectra S2, Spectra S2 Plus and Spectra S1. This set includes one each: tubing, valve and backflow protector as well as the large 28mm breast flange. To assure quality, these replacement parts are genuine Spectra brand replacement parts.