Xtenex (indeXed-TENsioning-nEXus) is a patented elastic shoelace technology that produces adjustable tension between shoe eyelets. Featuring an elastic core and series of knots at consistent intervals along the lace, the knots disappear when stretched to allow for threading through eyelets. When released the knots reappear maintaining optimal fit by limiting involuntary movement; increasing comfort and keeping the foot stable. alleviates blisters eliminates binding and restriction adjustable for pain & pressure point relief maintains a customized, reliable fit eliminates untied, loose laces effectively turns performance shoes into slip-ons