View irf520n datasheet:

PD - 91339A IRF520N HEXFET® Power MOSFET Advanced Process Technology D Dynamic dv/dt Rating VDSS = 100V 175°C Operating Temperature Fast Switching RDS(on) = 0.20? Fully Avalanche Rated G Description ID = 9.7A S Fifth Generation HEXFETs from International Rectifier utilize advanced processing techniques to achieve extremely low on-resistance per silicon area. This benefit, combined with the fast switching speed and ruggedized device design that HEXFET Power MOSFETs are well known for, provides the designer with an extremely efficient and reliable device for use in a wide variety of applications. The TO-220 package is universally preferred for all commercial-industrial applications at power dissipation levels to approximately 50 watts. The low thermal resistance