I love these because they are flat laces. I use them in the sneakers that I'm too unmotivated to tie and untie, so I just keep them tied and slip the sneakers on.  I wear the sneakers to exercise (they are not high tops) and this brand of laces have been in the shoes for about 6 months with no problems.  I expect that at some point they will snap from all the stretching to put the sneakers on, but that hasn't happened yet.  I wear a size 7 mens sneaker for exercise because I find the width more comfortable than womens' sneakers (I am 8.5 W in womens).  I bought the absolutely longest length lace that they sold and I do have extra left over to make a reasonably-sized bow.