This part is a kind of semiconductor called TIP142.

Function of this product has Monolithic Construction With Built In Base- Emitter Shunt Resistors.

Manufacturers : Fairchild Semiconductor

Image and pinout :

Some of the text within the PDF file :

TIP140/141/142 TIP140/141/142 Monolithic Construction With Built In BaseEmitter Shunt Resistors • High DC Current Gain : hFE = 1000 @ VCE = 4V, IC = 5A (Min.) • Industrial Use • Complement to TIP145/146/147 1 TO-3P NPN Epitaxial Silicon Darlington Transistor Absolute Maximum Ratings TC=25°C unless otherwise noted Symbol VCBO Parameter Collector-Base Voltage : TIP140 : TIP141 : TIP142 Value 60 80 100 60 80 100 5 10 15 0.5 125 150 - 65 ~ 150 Units V V V V V V V A A A W °C °C 1.Base 2.Collector 3.Emitter Equivalent Circuit C VCEO Collector-Emitter Voltage : TIP140 : TIP141 : TIP142 Emitter-Base Voltage Collector Current (DC) Collector Current (Pulse) Base Current (DC) Collector Dissipation (TC=25°C) Junction Temperature Storage Temperature B VEBO IC ICP IB PC TJ TSTG R1 R [ ... ]

TIP142 PDF Datasheet Download