· Contains 2x 17mm Maymom widemouth flanges compatible with spectra s1 pump, s2 pump and 9 pump. Suitable for mother with a nipple diameter 14-15 mm (measured AFTER a pumping session). Suitable for spectra s2 accessory replacement.· BPA free; Complies with US FDA regulation for plastics that contact foods· Compatible with spectra wide mouth bottles, AVENT bottles, and Maymom wide mouth bottles. They are NOT compatible with OTHER wide mouth bottles.· Made by Maymom, not original spectra company. Maymom is not affiliated with Uzinmedicare, the trademark owner of spectra.· Dishwasher toprack safe; Steam safe;