This CDI is a replacement unit for all year Octane models and any 2 cyl model with an existing update kit installed. This is a HST timed CDI box. *Please be advised - when installing a replacement Polaris domestic CDI it is extremely important to verify correct flywheel timing. Refer to a Polaris service manual for your specific models timing and time accordingly after the new CDI is installed. *Failure to follow this recommendation can result in piston deterioration and possible engine failure.