Features: 1.It can change the motor of different diameter shafts and change the belt pulleys of different speeds. 2.It reduces the need to purchase new motors or pulleys to maintain existing components and speed/power requirements. 3.Adapt the larger wheel hole to the small shaft and work with the pneumatic crank shaft. 4.Increase the crank diameter to accommodate pulleys, gearboxes, etc. 5.The inner diameter of the sleeve is 5/8inch, the outer diameter of the sleeve is 3/4inch, the shaft length is about 3inch, and the sleeve key groove is 3/16inch. Specification: Features:_x000D_ _x000D_ It can change the motor of different diameter shafts and change the belt pulleys of different speeds. _x000D_ It reduces the need to purchase new motors or pulleys to maintain existing components and speed/power requirements. _x000D_ Adapt the larger wheel hole to the small shaft and work with the pneumatic crank shaft. _x000D_ Increase the crank diameter to accommodate pulleys, gearboxes, etc. _x000D_ The inner diameter of the sleeve is 5/8inch, the outer diameter of the sleeve is 3/4inch, the shaft length is about 3inch, and the sleeve key groove is 3/16inch. _x000D_ The sleeve and key holder are designed to fit snugly over your 5/8inch diameter crankshaft with a 3/16inch keyway and extend to 3/4inch diameter with a 3/16inch key holder. _x000D_ _x000D_ Specifications:_x000D_ Condition: Brand New_x000D_ Material: Aluminum alloy_x000D_ Color: Shown as picture_x000D_ _x000D_ Package List:_x000D_ 1 * Round Shaft_x000D_ 1 * Long Key PackageList: