Fits CRF/XR50, CRF/XR70, CRF/XR80, CRF/XR100, CRF150F, and CRF230F to eliminate the 9800 rpm rev limiter and provides a hotter advance curve. Features: - Eliminates the 9800 rpm rev-limiter of the OEM ignition - Direct replacement for the OEM CDI ignition box - A must have for the new CRF150F and CRF230F!