HOT transmission oil has to be COOLED to keep you on the track. Double stacked cores deliver over 40,000 BTU/HR of cooling and over 350% temperature drop versus the factory system - 36% better temperature drop than BD's standard single core kit. The 200 Micro Extruded passages provide a large surface area to transfer heat for external air flow cooling while turbulent oil flow design promotes a more complete cooling. Large 5/8-inch ports prevents inlet/outlet restriction and furnace brazed rails have been tested to 300psi of pressure. The thermostatically controlled 80-watt, 10-inch, 800 CFM electric fan offers ultimate automatic oil temperature control.