This part is a kind of semiconductor called SSP4N60AS.

Function of this product has Advanced Power MOFET.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

Advanced Power MOSFET FEATURES Avalanche Rugged Technology Rugged Gate Oxide Technology Lower Input Capacitance Improved Gate Charge Extended Safe Operating Area Lower Leakage Current : 25 µ A (Max.) @ VDS = 600V Lower RDS(ON) : 2.037 Ω (Typ.) SSP4N60AS BVDSS = 600 V RDS(on) = 2.5 Ω ID = 4 A TO-220 1 2 3 1.Gate 2. Drain 3. Source Absolute Maximum Ratings Symbol VDSS ID IDM VGS EAS IAR EAR dv/dt PD TJ , TSTG TL Characteristic Drain-to-Source Voltage Continuous Drain Current (TC=25 C) Continuous Drain Current (TC=100 oC) Drain Current-Pulsed Gate-to-Source Voltage Single Pulsed Avalanche Energy Avalanche Current Repetitive Avalanche Energy Peak Diode Recovery dv/dt Total Power Dissipation (TC=25 oC) Linear Derating Factor Operating Junction and Storage Temperature Range Maximum Lead [ ... ]

SSP4N60AS PDF Datasheet Download