Ameda Custom Breast Flanges with Inserts - BPA Free X-Large (32.5 mm) and XX-Large (36 mm)New BPA Free design! Research has shown one-third or more new mothers pump more comfortably and effectively with a larger flange! When do you need a larger flange size? If you feel discomfort when pumping, even on low suction, or pump less milk than you believe you should.Our Custom Breast Flanges replace standard flanges (25mm) included with most Ameda pumps and kits. Each box includes two flanges and two inserts – so there’s no chance of buying the wrong size.