Rails are wider (48") for faster install, because the mounting points are outside the truck frame, allowing the installer to avoid under-bed components. Grade 8 hardware meets all Canadian requirements. If Pull Pins are needed, kit 58467 is available to be purchased separately. SAE J2638 Compliant based on heavy duty, accelerated life cycle criteria developed by SAE for fifth wheels. J2638 are fatigue and static requirements based on the European style test of 900,000. Includes a limited lifetime warranty.