22 mars 2023 · How much areola in flange? Lansinoh has a range of five flange sizes to choose from. Breast flanges are usually measured in millimeters, referring to the diameter of the tunnel. Lansinoh’s standard size is 25mm, and additional sizes offered are 21mm, 28mm, 30.5mm, and 36mm.) Pumping is hard work, and you want to get the most out of every.