Great way to extend your YFZ 450's rear end, Better than billet spacers. The axle offers different lengths to choose from, Just by changing around spacers. Easy to make adjustments, Splines, Castle nuts and cotter pins all look well made. These allow you to use your OEM lock nut unlike others that use the 3 piece design. I have owned several LSR and RPM axles and prefer these 2 brands over all. Don't cheap out with a off brand axle, Do it right the first time! LSR make great products and have been in the industry a long time. Support the company that support us riders, Affordable, Durable parts!