Maymom's backflow protector can replace both Spectra's new and old versions of backflow protectors. It completely separates the milk from the tubing to protect the tubing and your pump motor. It is an ideal solution for your spectra s2 accessories and spectra s1 accessories. If you are looking for pump parts for spectra, Maymom is your first choice.<p> Maymom is a company making breastpump parts compatible with Medela, Ameda, Avent, spectra and Hygeia pumps. It has more than 5 years in experiences in this field. Buying Maymom's product is backed up by 100% satisfaction guaranteed!.</p>