One replacement 1-3/8" X 21 spline clutch hub for PTO slip clutches, replaces 160 mm diameter clutch hubs that use two friction disc, will not fit 4 friction disc units. These are new OEM clutch hubs. Designed to mount via two cinch bolts. Specifcations: OD: 160mm or 6.29" ID: 35mm (1-3/8") with 21 splines Fits Eurocardan FD2 Series Clutches