Features: Ensuring easily breastfeeding experience with these replacement part, designed exclusively for compatibility for S18/S21 breast pumps. Upgraded 24mm/27mm single sealed flange, this collector cup accessories enhances milk collection efficiency by improving sealing. Great for breastfeeding mother seeking reliable and comfortable pump accessories, ensuring easily lactation process. Perfect for use at home, in office, or while traveling, provide convenience and ease for mom during travel. Craft from quality food grade silicone and pp, easy to clean, essential addition to your breastfeeding essential. Specifications: Component: Silicone+PP Size: 24mm, 27mm(optional) Breast Pump Milk Collector: approx. 120x110mm/4.72x4.33inch Duckbill Vaves: approx. 25x20mm/0.98x.78inch Diaphragm: approx. 40x55mm/1.57x2.16inch Dust Cover: approx. 115x125mm/4.52x4.92inch Flange: approx. 120x110mm/4.72x4.33inch Applicable Model: for S18/S21 electric breast pump Package Includes: 1 Piece Breast Pump Milk Collector 1 Piece Duckbill Vaves(1pc, not multiple) 1 Piece Diaphragm 1 Piece Dust Cover 1 Piece Flange note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.