COMPATIBLE MODELS – PumpMom adapter for Spectra backflow protectors compatible Spectra S1,S2 and 9 pump to use most Medela shield and Personfit connector. Will NOT compatible with Medela Freestyle and Swing-Maxi Pumps. Using PumpMom flange adapter to connect Spectra pump to compatible with Medela breast shields flanges and other accessories. Easy to Use- Only you need to do is plug the backflow adapter into(compatible with Medela) pump parts, then attach the Spectra tube/ backflow protector to the adapter. SAFE MATERIAL -Made with Food Grade Polypropylene(PP), BPA/DEHP Free. IN RETAIL PACK, SEALED BY MANUFACTURER.