2x One-Piece Breastshield (24 mm, suitable for mothers with niple diameters of 22-23 mm AFTER a pumping session), 2 Valves, 4 Membranes; Compatible with all Medela pumps EXCEPT FreeStyle, Maxi, Sonata, Harmony, Pump in style with maxflow. US FDA registered medical device (No. D192499); Products are inspected by US FDA. Complies with US FDA and EUstandards for containers that contact food and class II medical device; Test reports are online for your reference; Retail poly-bag packed; sealed by the manufacturer - Maymom, not original Medela parts Made of Bisphenol-A (BPA)/DEHP-free material and all components are steam safe for sterilization. Available in various sizes (13, 15, 17, 19, 21, 24, 25, 26, 27, 29, 30, 36 mm) for purchase.