Hayden Automotive 778 Rapid-Cool 37mm Heavy Duty Engine/Transmission Cooler Size is 1-3/4 inch X 8-7/8 inch X 12-15/16 inch Class "A" motor homes, large travel trailers, 5th wheel trailers GVWR up to 30,000 pounds, towing up to 10,000 pounds Plate and fin, heavy duty, high capacity design 12 fittings for maximum flow capacity