Used by team Honda Pro racers; This stabilizer is extremely adjustable and rugged. The unit comes with all hardware needed for an easy installation and mounts up to your 450R in approximately 15 minutes; no drilling, welding, or grinding needed. The Pro stabilizer has a built in reservoir to compensate for thermal expansion. The stock steering stem diameter for the TRX450 is 1.35". If your aftermarket stem is a different size, please choose the correct diameter from the pull-down list below.