Third generation Power MOSFETs IRF9540 SiHF9540 from Robodoc provide the designer with the best combination of fast switching, ruggedized device design, low on-resistance and cost-effectiveness. The TO-220 package is universally preferred for all commercial-industrial applications at power dissipation levels to approximately 50 W. The low thermal resistance and low package cost of the TO-220 contribute to its wide acceptance throughout the industry.
http://www.futurlec.com/Transistors/IRF9640.shtml
http://www.futurlec.com/Transistors/IRF9640.shtml