Nursi Luna Flange Sizing Kit with Silicone Flange Inserts - 10PCS (13/15/17/19/21mm), Reduces 24mm Tunnel to Correct Size Our flange insert set is one of the pumping essentials every mom needs. These silicone flange inserts are designed to provide maximum comfort and efficiency during milk expression. Made from high-quality, BPA-free, food-contact..