When designing the new Lightweight Enhanced (LE) Castle Nut & End Plate System, Fortis came up with two systems that virtually eliminates the risk of your castle nut ever backing out. With the two lockdown systems (K1 & K2), they’ve engineered a solution to install the castle nut onto the end plate that is not only robust, but also stands true to the brand of innovation and ingenuity. The K2 system utilizes a locking lever design that seats itself through a designed slot on the bottom of the end plate and into corresponding cutouts on the castle nut. This ultra precision fit allows the castle nut to seat itself into place without the need of staking the end plate. No set screws, no backing out and no failures. All of these features at only .53 oz / 15 grams!