Lock Elastic Shoe Laces &ndash; High Technology Device &ndash; Super Strong Nylon Lock &ndash; Alloyed Spring &ndash; Avoid Rusting Corrosion &ndash; Durable &ndash; Guaranteed Right, Constant and Stable Tension &ndash; Black Easy to use Stretch-fit comfort Locked-in safety Water resistant Great for running, triathlon and other sports - Ideal for kids, seniors and individuals with special needs