The gearboxes for all Hummer 2-seater models are the same. However, the gearbox for Yellow and Black models comes with 1/2" hatnut (for 12" wheel). And the gearbox for Red and Pewter models comes with a 5/8" hatnut (for 14" wheel).
WARNING: This product contains one or more chemicals, including lead, known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.