This part is a kind of semiconductor called BD137.

Function of this product has Plastic Medium Power Silicon NPN Transistor.

Manufacturers : Motorola Inc

Image and pinout :

Some of the text within the PDF file :

MOTOROLA SEMICONDUCTOR TECHNICAL DATA Order this document by BD135/D Plastic Medium Power Silicon NPN Transistor . . . designed for use as audio amplifiers and drivers utilizing complementary or quasi complementary circuits. • DC Current Gain — hFE = 40 (Min) @ IC = 0.15 Adc • BD 135, 137, 139 are complementary with BD 136, 138, 140 BD135 BD137 BD139 1.5 AMPERE POWER TRANSISTORS NPN SILICON 45, 60, 80 VOLTS 10 WATTS ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎÎ [ ... ]

BD137 PDF Datasheet Download