20-7/16″ S-Cam Length (Fits s-cam length range of 20-3/8″ through 20-7/16″) Extreme Cam Tube Length: 17-1/8″ 1-7/8″ Spider Diameter Left-Hand 28 Spline 1.5″ S-Cam Journal For use with Trailers only Bolt-On; no welding required