My heater is similar in size and shape to the link above, but not the same product. My heater is original equipment (or maybe I should say very old). It has louvered doors on the front and a six-volt motor. The motor has a shaft on both sides. One shaft drives a fan blade for pushing air into the cab and the other shaft drives a squirrel cage for pushing air to the defrosters. The only way to control the air flow is to adjust the louvered doors in front. Open them (by hand) to get more air into the cab. Close them to push more air to the defroster. The only legible writing on the unit is "B&B Deluxe" which is stamped on the front of the unit.
