Features: Ensure efficient milk expression with these replacement part for s18/s21 breast pump. These reliable and easy to clean silicone Replacement provide a hygienic pumping experience, compatibility with electric breast pumps. Easy for breastfeeding mom, these replacement part offer flexibility and comfortable during milk expression. Expression milk comfortably anywhere at home, in office, while travel with these reliable replacement part. With a securely fit and smooth milk flow, these replacement part help maintain a steady milk supply. Specifications: Material: Silicone+PP Size: about 46x40mm/1.81x1.57inch, 11x11.8cm/4.33x4.64inch Applicable Model: for S18/S21 Electric Breast Pump Package Includes: 1x Silicone Diaphragm 1x Valves 1x Milk Collector 1x Flange note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.