Replacement CDI for all 900, 1050 models. This is a non HST timed ignition 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.