I've amassed quite a collection of running/walking/working shoes, and I have to tell you, I've always hated tying laces.  I hate tying laces because they come undone, or if I tie them double, they take a long time to undo.  No more, not with these guys.  I suggest going with the 34 inch size. They will fit most sneakers. If you like a real tidy look, the 30s will work on a lot of shoes and there will be little left over to dangle in front of the shoe.  Anyway I've saved enough time not tying my shoes to write a dozen or so product reviews on Amazon!