Bus 450 was an MAN SG192 articulated bus. It entered service on 27 September 1976, making it the first European-style articulated bus to enter regular service in Australia.
Along with 510, 532 and later 671, this vehicle was fully-imported from Germany with the front section bodied by MAN, Penzberg and the trailer section bodied by Göppel Bus, Augsburg.
Unlike later articulated buses to be operated by ACTION, the MAN SG192 was a mid-engined bus which drove the middle axle only.
Bus 450 was withdrawn from regular service around late 1990, but was retained for a time as part of the ACTION Heritage Fleet and at the same time was used for driver training.