The CamJam XT Aluminum Rope and Cord Tighteners feature Nite Ize signature, knot-free CamJam tightening and tensioning technology. The XT holds cord from 1/16 in. - 3/16 in. [2 mm-5 mm] in width. To use the Fixed End System: simply anchor the carabiner to any hook, D-ring, or loop, and feed the cord or rope through the cam until you've reached the desired level of tension.