Top of the range heavy-duty elastic cord laces perfect for speedy transitions! You simply replace your laces with these elastic cords, use the dual cord-stopper to adjust the tension, & tie off the ends, so they don't slip through the cord-stopper. The ends of the laces are also shrink wrapped to prevent fraying & also have a built in reflective weave for night training. The elastic laces are strong enough to be adjusted to any desired tension. They are robust enough to withstand at least a season of constant use (also in training) & abuse in the sun (UV) & moisture (salty sweat). The cord lock uses a stainless steel spring, so it won’t rust or freeze up.