Features:This steel shaft sleeve adapts a crankshaft from 3/4 inch to 1 inch diameter, it comes with step key that offsets from 3/16 inch to 1/4 inch.Alters motors with a different diameter shaft and alters pulleys for a different speed or belt.Reduces the necessity of buying a new motor or pulley to maintain existing components and speed/power requirements.Adapts larger wheel bores to smaller axles, works with Gas Engine Crank Shafts to enlarge the crank diameter to fit pulleys, gear boxes etc.One adapter and step key included; Made from cold rolled steel, CNC precision machined and tumbled, high durability.Specification:Condition: 100% Brand NewItem Name: 3/4 inch to 1 inch Crank Shaft Sleeve AdapterMaterial: SteelColor: SilverSleeve Inside Diameter: 3/4 inchSleeve Outside Diameter: 1 inchSleeve Length: about 3inchSleeve Keyway Slot: 1/4inchStep Key Length: about 2 inchPackage Weight: approx.138gPackage List:1 * 3/4 inch to 1 inch Crank Shaft Sleeve Adapter1 * Step Key