DO NOT BUY. These are designed to fail. If you look through the picture of them. there is one when the cans on a headphone stand you can see a little clear plastic piece between the head strap and the actual headphone. THAT ALWAYS BREAKS. I have had 3 of these and it always breaks after a few months.
b1oodyYeah happened to me, though they aren't structurally necessary for the headphones it does make them a bit looser.
Also the elastic wore down on one side for me.