>>The moms I've worked with who had nipples the size of quarters experienced discomfort pumping with the standard size opening on the M- kit. They did much better with the largest glass flange that can be special ordered.<< I've been having difficulty. I have Medela's extra large glass flange--- the one size fits all one, but it has been TOO large for the moms, while the regular flange has been too small. This is a real dilemma. There used to be more sizes, but currently aren't, at least to the best of my knowledge. Anyone out there with more info? -Lisa Marasco, LLLL, IBCLC Santa Maria, CA