Youha Silicone Membranes is a pair of replacement silicone diaphragms for The INs Gen 2 Breast Pump backflow protectors.It is ideal to replace your silicone diaphragm every 2-3 months, and less if you pump frequently. Replacing your diaphragm frequently is essential in keeping your breast pump working in top condition for best pumping experience. ForYouha The Ins Gen 2 Wearable Handsfree Breast Pump (click here). Contains 2x diaphragm only.