This part is a kind of semiconductor called MJE15030.

Function of this product has Complementary Silicon Plastic Power Transistors.

Manufacturers : ON

Image and pinout :

Some of the text within the PDF file :

MJE15028, MJE15030 (NPN), MJE15029, MJE15031 (PNP) Complementary Silicon Plastic Power Transistors These devices are designed for use as high−frequency drivers in audio amplifiers. Features • High Current Gain − Bandwidth Product • TO−220 Compact Package • These Devices are Pb−Free and are RoHS Compliant* MAXIMUM RATINGS Rating Symbol Value Unit Collector−Emitter Voltage MJE15028G, MJE15029G MJE15030G, MJE15031G VCEO 120 150 Vdc Collector−Base Voltage MJE15028G, MJE15029G MJE15030G, MJE15031G VCB Vdc 120 150 Emitter−Base Voltage Collector Current − Continuous Collector Current − Peak Base Current Total Device Dissipation @ TC = 25_C Derate above 25°C VEB 5.0 Vdc IC 8.0 Adc ICM 16 Adc IB 2.0 Adc PD 50 W 0.40 W/_C Total Device Dissipation @ TA = 25_C D [ ... ]

MJE15030 PDF Datasheet Download