This part is a kind of semiconductor called BC558.

Function of this product has PNP Silicon Amplifier Transistor 625mW.

Manufacturers : Micro Commercial Components

Image and pinout :

Some of the text within the PDF file :

MCC Features l Through Hole Package l 150oC Junction Temperature Pin Configuration Bottom View
  omponents 21201 Itasca Street Chatsworth    !"# $ %    !"# BC556,B BC557,A,B,C BC558,B PNP Silicon Amplifier Transistor 625mW C B E Mechanical Data l Case: TO-92, Molded Plastic l Polarity: indicated as above. A TO-92 E B Maximum Ratings @ 25oC Unless Otherwise Specified Charateristic Collector-Emitter Voltage Symbol Value -65 VCEO -45 -30 -80 VCBO -50 -30 VEBO -5.0 IC Pd Pd RqJA Unit V C Collector-Base Voltage BC556 BC557 BC558 BC556 BC557 BC558 V V mA mW mW/oC W mW/oC o D Emitter-Base Voltage Collector Current(DC) Power Dissipation@TA=25oC Power Dissipation@TC=25oC Thermal Resistance, Junction to Ambient Air Thermal Resista [ ... ]

BC558 PDF Datasheet Download