Koch Industries 4045423 Over Running Clutch 1000 RPM Maximum with 1-3/8 by 6-Inch Male Spline and 1-3/8 by 6-Inch Female Spline Connect implements to a tractor's PTO shaft Allows for power to be transferred from the tractor to the implement Male Spline 1-3/8 by 6 and Female Spline 1-3/8 by 6 1000 RPM Maximum Yellow zinc plated finish