Suitable Models: Universal Material: Stainless Steel Package Size: 7.5*2.5*2.5cm 3/4" to 1" Billet Shaft Adapter Pulley Bore Reducer Sleeve Bushing Sheave Key SL This steel shaft sleeve adapts a crankshaft from 3/4" to 1" diameter. It comes with a step key that offsets from 3/16" to 1/4". Applications: - Adapts motors with different diameter shafts - Adapts pulleys for different speed or belt requirements - Reduces the need to replace motors or pulleys to maintain existing component compatibility - Adapts larger wheel bores to smaller axles - Works with gas engine crankshafts to enlarge crank diameter for pulleys, gearboxes, and similar components Parts Specification: - Sleeve inside diameter: 3/4" - Sleeve outside diameter: 1" - Sleeve length: approximately 3" - Keyway slot: 1/4" - Step key length: approximately 2" The sleeve and step key are designed to provide a precise fit on a 3/4" diameter crankshaft with a 3/16" keyway and extend it to a 1" diameter with a 1/4" keyway. Professional installation is highly recommended. No instructions are included. All items are new unless otherwise stated. This is a DIY (Do It Yourself) item with limited exceptions. The seller does not provide installation guidance. Professional installation is strongly advised.