Features: 1.One adapter and step key included; Made of quality material, high durability. 2.Adapts larger wheel bores to smaller axles, works with Gas Engine Crank Shafts to enlarge the crank diameter to fit pulleys, gear boxes etc. 3.Alters motors with a different diameter shaft and alters pulleys for a different speed or belt. 4.Reduces the necessity of buying a new motor or pulley to maintain existing components and speed/power requirements. 5.This steel shaft sleeve adapts a crankshaft from 3/4'' to 7/8'' diameter, it comes with 3/16'' step key. Specification: Features: This steel shaft sleeve adapts a crankshaft from 3/4'' to 7/8'' diameter, it comes with 3/16'' step key. 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 of quality material, high durability. Specification: Condition: 100% Brand New Item Name: Crank Shaft Sleeve Adapter Material: Aluminium alloy Color: As Pictures Show Sleeve inside diameter 3/4'' Sleeve outside diameter 7/8'' Sleeve length is about 3'' Sleeve Keyway slot 3/16'' Keystock Length: about 2'' Package List: 1 * Crank Shaft Sleeve Adapter 1 * Keystock PackageList: