This one way starter clutch gear assembly with bearing and flywheel is designed for use with TRX400EX models from 1999 to 2008 and TRX400X models from 2009 to 2014.The component functions to engage the starter motor with the engine crankshaft during ignition and disengage once the engine is running.This part serves as a functional replacement to restore starting system.Compatibility is limited to the specific model years and designations listed in the product title.Installation requires standard mechanical tools and adherence to the vehicle manufacturer service manual procedures.