The Maxx Cap slides into the end of the MAXX TRAX 2000 Series lengths and has a locking Allen screw for a secure fit. Place notched end of the Maxx Cap into the (female) matching profile of the MAXX TRAX 2000 Series end, with the flat surface down and the Allen screw facing up. Slide Uni Cap into the trax until it butts up firmly against the flat end of the trax. Using the supplied Allen wrench, tighten down on the Allen screw to secure it in place on the Uni Trax.