Apico steel rear sprockets are manufactured using an aerospace grade light weight C45 Medium Carbon Steel. Cad Designed for enhanced tolerances and CNC machined laser cut profile for improved weight reduction and strength throughout. A standard feature with all Apico rear sprockets are the clearing grooves around the outer edges of the sprockets. Theses help to remove any build-up of mud and reduce ware and additional stress to the sprocket. Finished with a Cataphoresis Electro Coating giving them a unique look and unrivalled anti-corrosive properties. STEEL REAR SPROCKET - BLACK YAMAHA YZ65 18-25