Fits Up to 4" Frame Allows consumers to upgrade from a Fulton Center-Bolt Swivel Mount Jack to an F2 Jack Fits Fulton's patented center-bolt design used on XP10 and XP15 weld-on jacks Maintains the smooth factory appearance of your trailer Mount is tapered, moving wheel closer to trailer frame to optimize castering Installs easily-no drilling or welding All mounting hardware included Limited 5 year warranty