This bearing starter clutch assembly is designed as a direct replacement part to restore starting function.Constructed from forged steel, this unit fits WR250F (2003, 2015-2018), YZ250FX (2015-2018), WR450F (2003-2006, 2011-2018), YZ450FX (2016-2018), YZ250F (2015), YZ450X (2016), YZ250X (2016), YFZ450, and YFZ450R (2009-2018) models.The component corresponds to OEM code 5TJ-15590-00-00.This listing includes one set of the starter clutch assembly.Please verify your motorcycle model and year against the compatibility list before purchase to ensure proper fitment.