Popular transistors.

TIP122 transistor.
Pinout. Datasheet.

Type Designator: TIP122.
Package: TO-220, 1-base, 2-collector, 3-emitter.
Material of transistor: Si
Polarity: NPN
Total Devise power dissipation |PD|: 65W
Collector-base breakdown voltage |VCBO|: 100V
Collector-emitter breakdown voltage |VCEO|: 100V
Emitter-base breakdown voltage |VEBO|: 5V
Maximum collector current |Ic max|: 5A
Maximum junction temperature |Tj|: +150 C
Transition frequency (ft) : 3MHz(min)
Output Capacitance |Cob|:200pF
Collector-emitter saturation voltage|VCE|:2V(IC=3A,IB=12mA)
Forward current transfer ratio |hFE| : 1000(IC=0,5 A,VCE=3V)