BabyBuddha EasyFit 21mm Flange Kit.Our EasyFit flange features a flexible edge for maximum suction and comfort.The flange commonly known as a breast shield, is a funnel-shaped plastic or silicone piece that fits directly over your nipple to form a seal around your areola. It creates a vacuum that gently draws your nipple into the funnel for milk removal, depending on the size of your nipple, you may need an insert for a better fit. Replace breast pump flanges every 6-12 months. You can extend the life of your flange by cleaning it thoroughly after each use. However, even a well-cared-for flange will need to be replaced after 12 months of use. Compatible only with the BabyBuddha Pump. Do not clean in dishwasher or microwave steam bags. BPA Free. Includes:- Two (2) 21mm Flange and assembly kits.- Two (2) Duckbill Valves.- Two (2) Silicon Diaphragms.