Model Compatibility: Fits Y0302.5A8, XB9SX, XB12S, XB12SX, XB12STT, XB12SS, XB12SCG, XB12R, Firebolt XB12X, and XB12XP motorcycles as a direct replacement voltage regulator rectifier. Technical Specification: Matches the voltage regulator rectifier function for the listed motorcycle models without altering electrical output characteristics or operational behavior. Installation Note: Installs in the same location and orientation as the unit using existing mounting points and wiring connections on compatible models. Functional Purpose: Restores regulation of alternator output voltage and conversion of AC to DC current as required by the on specified motorcycles. Application Scope: Designed as a functional replacement for the voltage regulator rectifier component on the motorcycle models explicitly named in the title.