ITEM NAME:1 Set Metal 3/4 to 1 Shaft Adapter Pulley Bore Reducer Sleeve Bushing Sheave Key Description: Alters motors with a different diameter shaft Alters pulleys for a different speed or belt Adapts larger wheel bores to smaller axels Reduces the necessity of buying a new motor or pulley to maintain existing components and speed/power requirements. Works with Gas Engine Crank Shafts to enlarge the crank diameter to fit pulleys, gear boxes etc. Specification: Sleeve inside diameter 3/4†Sleeve outside diameter 1†Sleeve length is about 3†Sleeve Keyway slot 1/4†Step Key Length is about 2†Size Chart: Size:75x25mm Package Includes: 1x 3/4 to 1 inch shaft adapter Note: The color may have different as the difference display, pls understand. Please allow 1-3mm error due to hand test. Thank you for your understanding and finding this item. Enjoy your shopping timeï ¼ SKU: DMO0000011652030246.Step Key Length is about 2†. Adapts larger wheel bores to smaller axels. Sleeve length is about 3†. Sleeve Keyway slot 1/4†. Alters pulleys for a different speed or belt. The color may have different as the difference display, pls understand.