Available in various sizes (13, 15, 17, 19, 21, 23, 24, 25, 26, 27, 29, 30, 32mm) for purchase. Made of Bisphenol-A (BPA)/DEHP-free material and all components are steam safe for sterilization. Retail poly-bag packed; sealed by the manufacturer - Maymom, not original Medela parts. 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;. 2x shields (23 mm, suitable for mothers with nipple diameter AFTER pumping 21-22 mm) , Compatible with Medela pumps (New Medela Pump in Style with MaxFlow, Pump in style, Lactina, Symphony, Swing, Mini Electric FreeStyle, Swing Maxi, Sonata, Freestyle Flex and Harmony). NOTE: connectors are not included in this listing. Not original Medela pump parts.