This listing is for one replacement Howse Rotary Cutter Gearbox, 4 bolt mounting with bolt hole centers of 8" This gearbox has a 1-3/4" diameter 20 spline input shaft and the output shaft is 2" (1.97") with 15 tapered splines. The box has what we call a diamond bolt pattern where the is a mounting hole directly under the input shaft, and each other mounting hole is 90 degrees from the previous hole. The gear Ratio of this box is a 1:1.46 speed up Box Specifications: Heat Treated Precision Gears High Speed Tapered Roller Bearings on Input and Output Shafts 1-3/4" X 20 Spline Input Shaft 1.97" X 15 Tapered Spline Output Shaft Includes Castle Nut and Cotter Pin Note: All gearboxes are shipped dry and require that add 80, 80-90, 90-120 or equivalent gear old prior to use, We recommend a synthetic gear lube. We sell many replacement rotary cutter parts. If you don't see the parts you need listed please contact us we would love to earn your business. We are listing new items frequently so please check our store often. Replaces Part Numbers: 575RC71146 We stock a wide variety of replacement parts for Agricultural Equipment please contact us if you have any questions or if you would like more information.