I see the specs for the M and U-fit, but what is the difference in the actual fit? The Ms have a little tab to pull the plugs out with, but nothing on the U; is that the major difference?
amkaplanThe M comes with two sets of tips, the U similar in size to the smaller set. As a side note, the U comes with a strap that attaches to the ends of the plugs so they're easier to take out.