1950/51 GM TDH-4509 (Metropolitan Bay Transit Authority 2600-2669 series).
In December 1950 - March 1951 Boston's Metropolitan Transit Authority acquired a
fleet of 70 TDH-4509 buses. Satisfied with new GM product, MTA later acquired a large number of the TDH-5104/5106 and TDH-5105 buses.
New model - Pre-order