Replacement 75hp Gearbox for International Rotary Cutters, Fits all 75hp models. Features 1-3/8" Input Shaft with 6 Splines, a 1.97" Diameter Output Shaft with 15 Tapered Splines, a 8" Mounting Pattern with one mounting hole directly under the input shaft. These are sold in either a square or round housing and they are interchangeable.