Comfort

Firstly, these don't lengthen or cause the mask to ease up if it is already tight.  I thought it might for a couple of masks I have which just are too 'short.'  However, these will make the mask fit snugly if it already does and most importantly, not tug on your ears!  Makes it infinitely easier to wear for long periods as it evens out the 'pull' all across the back of your head instead of just pulling on your ears- so it's not really any more noticeable than say, a headband feels.  Feels secure and makes a good seal.  A really excellent, simple, affordable solution!