Contents: 2 Shields (17mm), 2 Wide-mouth Connectors, 2 Duckbills (3rd Gen). The 19mm shield is suitable for mothers with nippie diameter 15-16mm AFTER pumping . The shield and connector constitute a breast pump flange. The whole set works for double pumping Flange Features: Separable TWO-PIECE flange compatible with spectra pump, NOT like one-piece Spectra flange. Made by Maymom. Two-piece construction is preferable for easy assembly, disassembly and cleaning. It also fits most hands free pumping bra on the market and home-made bra. Available shield sizes : 10mm, 12mm,13mm, 15mm, 17mm, 19mm, 21mm, 23mm, 24mm, 25mm, 27mm, 28mm, 30mm, 32mm, 34mm,36mm. Compatibility: This set is compatible with Spectra Pump S1, Spectra S2, Spectra 9 Plus. Compatible ONLY with widemouth(wideneck) bottle, like Spectra wide-neck bottle, Maymom widemouth bottle. To make it compatible with Medela bottles, try Maymom 3rd Gen Bottle Converter (Amazon ASIN: B07MGSNJYJ). Regulations : All parts that come in contact with breast milk are BPA/DEHP free. Made by a US FDA inspected company, Maymom. Refer to her online access for test reports. Retail poly-bag packed; sealed by the manufacturer, Maymom. NOT original Spectra flange, NOT original Spectra pump parts. NOT original Spectra S2 Accessories. NOT original Spectra S1 accessories. ASIN B0B4NXNTK7 Size 17mm Brand Name Maymom Unit Count 2 Count Manufacturer Maymom Model Number S012W.B-Fxx Product Style 17mm Additional Features Double Pump, Hands Free Usage Included Components Breast Flange Manufacturer Part Number S012W.B-F.D.bx2 Is the item dishwasher safe Yes