This part is a kind of semiconductor called S8550.

Function of this product has TRANSISTOR (PNP).

Manufacturers : Wing Shing Computer Components

Image and pinout :

Some of the text within the PDF file :

S8550 TRANSISTOR (PNP) TO-92 FEATURES Power dissipation PCM : 0.625 W （Tamb=25℃） Collector current A ICM : - 0.5 Collector-base voltage V(BR)CBO : - 40 V 1 2 3 1. EMITTER 2. BASE 3. COLLECTOR ELECTRICAL CHARACTERISTICS（Tamb=25℃ Symbol voltage voltage V(BR)CBO V(BR)CEO V(BR)EBO ICBO ICEO IEBO HFE（1） unless otherwise specified） Test conditions IE=0 IB=0 IC=0 IE=0 IB=0 IC=0 85 50 MIN TYP MAX UNIT V V V Parameter Collector-base breakdown Ic= -100μA , Ic=- 0.1 mA， IE=-100μA， VCB= -40 VCE=-20 VEB= - 3 VCE= -1 V, VCE= -1 V, V, V, V， - 40 - 25 -5 Collector-emitter breakdown Emitter-base breakdown current current current voltage Collector cut-off Collector cut-off Emitter cut-off - 0.1 - 0.2 μA μA μA - 0.1 300 IC= 50mA IC= 500mA DC current gain(note) H [ ... ]

S8550 PDF Datasheet Download