Lippert 337113 RV and Trailer ToyLok Bumper Mounting Kit Attaches ToyLok anti-theft device to 4" x 4" RV and trailer bumpers This kit allows owners to attach their ToyLok anti-theft device to any 4" x 4" tube RV or trailer bumpers Works with both models TL1020 and TL2021 Easy do-it-yourself installation Kit comes complete with adaptor plates and mounting hardware