This is a BRAND NEW aftermarket Yamaha YFZ450 rear axle.
This is a stock replacement axle, same size as the factory unit
It is heat treated, and stronger than the stock unit its designed to replace
It will fit any year Yamaha YFZ450 2004-2009, but the nuts on the end are designed for the 2004/2005 style OEM #90171-14037-00
This uses all the stock components (nuts, carrier, hubs, etc) - and is a bolt on direct replacement for the OEM version.
This also will fit a Yamaha Blaster, and can be used to make it wider than the OEM factory blaster axle!