SARIS 3022 HITCHTITE LOCKING`HITCH TITE` (use on receiver Models) is a simple method to ensure a no slop hitch attachment A size specific metal sleeve w a nut welded to inside of it; This metal sleeve then slides into base of rack Line nut up w pre drilled hole in base Customer slides base into receiver hitch & uses special threaded hitch pin included, to tighten (Retro Kit available) Included with all locking models, e. g. Porter Hitch 4, Cycle On Pros, and Axis Aluminum