This tusk adjustable rear axle was tested on the 2013 Yamaha Raptor 700R, but we have heard great reviews of this product from riders on Yamaha YFZ450's and Raptor 350's. The axle easily slide into place, with the hardest part being the removal of the stock axle. We would suggest purchasing the axle nut wrench, which will help greatly in the removal and the installation. The new axle has held up quite nicely, yet we find it weird that Tusk tells you to re-use one of the stock C-clips. The axle is adjustable, thanks to spacers, but we would suggest putting a lock washer between the spacer and wheel as well as the wheel and spindle nut (we had an issue with the spindle nut coming loose even with using larger cotter pin key). In extreme riding conditions, the axle will quickly lose the shine it has out of the box. At a fraction of the cost of a stock replacement and other aftermarket axles; the tusk adjustable rear axle is a great choice for riders. We would like to remember everyone, that when widening the rear axle, one would need to widen to front end of the four wheeler as well. Visit Rocky Mountain ATV/MC to get yours today!