Mount the Atlas II truck seat in your truck with the help of this adapter kit. This kit allows the Atlas II to be installed in Peterbilt 579, 567 models and Kenworth 2.1, T680   and 2015 and older T660 models. Installation requires the removal of riser in truck. Kit includes 2 belts, 2 riser brackets (left and right), 4 centerlock nuts, four 7/16" hex nuts, 4 3/8" hex nuts, a bag, box, and tape.