Features: 1.Alters motors with a different diameter shaft. 2.Alters pulleys for a different speed or belt. 3.Reduces the necessity of buying a new motor or pulley to maintain existing components and speed/power requirements. 4.Adapts larger wheel bores to smaller axels. 5.Works with Gas Engine Crank Shafts to enlarge the crank diameter to fit pulleys, gear boxes etc. Descriptions: 1.The sleeve and step key are designed to exact fit on your 3/4” diameter crankshaft with 3/16” keyway and enlarge it to 1” diameter with 1/4” keyway. 2.Crankshafts are made of high quality metal, more durable. Specifications: Product Name: Shaft Adapter Set Material: Metal Color: Silver Sleeve Outside Diameter 1in Sleeve Length: Approx. 3in Sleeve Keyway Slot: 1/4in Step Key Length: Approx. 2in Package Informations: Package Size: 80x50x50mm/3.15x1.97x1.97in Package Weight: 140g/4.94oz General Package Package Included: 1 x Shaft Adapter Set Notes: 1.Due to manual measurements, please allow 1-2cm error.