This part is a kind of semiconductor called TIP122.

Function of this product has NPN Silicon Transistors.

Manufacturers : MCC

Image and pinout :

Some of the text within the PDF file :

MCC TM Micro Commercial Components
  omponents 20736 Marilla Street Chatsworth    !"# $ %    !"# TIP122 Features • Lead Free Finish/RoHS Compliant(Note 1) ("P" Suffix designates RoHS Compliant. See ordering information) • Darlington configuration in Jedec TO-220 package • The complementary PNP types are the TIP127 respectively. • Epoxy meets UL 94 V-0 flammability rating • Moisure Sensitivity Level 1 NPN Silicon Transistors Maximum Ratings Symbol VCEO VCBO VEBO ICP IC PC TJ TSTG Rating Collector-Emitter Voltage Collector-Base Voltage Emitter-Base Voltage Peak Collector Current Collector Current Collector power dissipation Junction Temperature Storage Temperature Rating 100 100 5.0 8.0 5.0 65 -55 to +150 -55 to +150 Un [ ... ]

TIP122 PDF Datasheet Download