This is the most popular model of TecNec by Cord-Lox, featuring patent-pending "closed loop" design. To use simply insert the end of the cord through the opening in the center section, and press firmly around the cord. This will keep it on the cord until you remove it. Next, coil or bundle the cord, wrap the Cord-Lox around it, and attach the hook side to the loop side. Cord-Lox will now keep your cords securely fastened and tangle-free, yet can easily be undone.