Nathan Lock Laces are easy to use, safe, and fun to wear with a simple installation and unique look. Never break your stride to tie your shoes again with the stretch fit and convenience of these laces.  Patented lock and clip system keeps laces secure and tight. Quick and easy one-time set up. Ideal for triathlons, marathons, and team sports. Ideal for kids, seniors, and individuals with special needs. Water-resistant.