When designing our new Lightweight Enhanced (LE) Castle Nut & End Plate System, we came up with two systems that virtually eliminates the risk of your castle nut ever backing out. With our two lockdown systems (K1 & K2), we’ve engineered a solution to install the castle nut onto the end plate that is not only robust, but also stands true to our brand of innovation and ingenuity. The K2 system utilizes a c-clip design that seats itself through a designed slot on the bottom of the end plate and into corresponding cutouts on the castle nut.