[Package Contents] A package of 8 replacement duckbill valves and 2 silicone membranes for use with the Spectra S2, S1, and 9 Plus breast pumps. [Compatibility] Pump parts are compatible with the Spectra S2, S1, 9 Plus, M1, Dew 350, and Motif Luna pumps. [Material Used] Crafted from food-grade silicone, it can be sanitized using water, steam, or boiling water. [Cleaning Tips] Rinse with clean water after washing with soap. Hard brushes should be avoided. Clean the thin tips with fingers. Do not use dishwasher. [Aftermarket Part] This is a PumpMom aftermarket item, Not Original Spectra S2 Pump Parts. Why Pumpmom? Pumpmom is an innovator, designer and manufacturer of breastfeeding, bottle feeding, toddler feeding products. We are driven by a strong desire to create seemingly insignificant products but help simplify parent's lives while retaining their personal style. We are a brand that you can 100% trust because we stand behind our products. We are committed to continuously improving our products using the feedback that we receive from users. Meeting this goal responsibly is at the heart of everything we do.