 It was for Certified Heating Co. Later buses would include painted advertisements for Crush, 7 Up, and Pepsi and were known as the "Pop" buses.In 1996 Oshawa Transit purchased five used 1981 General Motors T8H-5308A buses from Denver Regional Transit and assigned them bus numbers 146 thru 150.The Denver Regional Transit buses were distinct, aside from their higher bus numbers on older GMC buses within Oshawa Transit's fleet, in that they had the retrofitted air conditioning unit on the roof when they were purchased whereas the Oshawa Transit GMC buses of the same make did not.