This part is a kind of semiconductor called P4NK80ZFP.
Function of this product has STP4NK80ZFP.
Manufacturers : STMicroelectronics
Image and pinout :

Some of the text within the PDF file :
www.DataSheet4U.com STP4NK80Z - STP4NK80ZFP STD4NK80Z - STD4NK80Z-1 N-channel 800V - 3Ω - 3A - TO-220/TO-220FP/DPAK/IPAK Zener - Protected SuperMESH™ MOSFET General features www.DataSheet4U.com Type VDSS (@Tjmax) 800 V 800 V 800 V 800 V RDS(on) < 3.5 Ω < 3.5 Ω < 3.5 Ω < 3.5 Ω ID 3A 3A 3A 3A 3 1 1 3 2 3 1 2 STP4NK80Z STP4NK80ZFP STD4NK80Z STD4NK80Z-1 ■ ■ ■ ■ ■ TO-220 TO-220FP Extremely high dv/dt capability 100% avalanche tested Gate charge minimized Very low intrinsic capacitances Very good manufacturing repeatibility DPAK IPAK Internal schematic diagram Description The SuperMESH™ series is obtained through an extreme optimization of ST’s well established strip-based PowerMESH™ layout. In addition to pushing on-resistance significantly down, special [ ... ]