This part is a kind of semiconductor called 2SA1021.

Function of this product has POWER TRANSISTOR.

Manufacturers : Inchange Semiconductor

Image and pinout :

Some of the text within the PDF file :

www.net Inchange Semiconductor Product Specification Silicon PNP Power Transistors 2SA1021 DESCRIPTION ·With TO-126 package ·High breakdown voltage ·Large current capacity APPLICATIONS ·For color TV sound output;converters Inverters applications PINNING PIN 1 2 3 Emitter Collector;connected to mounting base Base DESCRIPTION Absolute maximum ratings(Ta=25℃) SYMBOL VCBO VCEO VEBO IC ICM PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector current-Peak Ta=25℃ PC Collector power dissipation TC=25℃ Tj Tstg Junction temperature Storage temperature 20 150 -55~150 ℃ ℃ CONDITIONS Open emitter Open base Open collector VALUE -150 -150 -6 -1.5 -2.5 1.0 W UNIT V V V A A Inchange Semiconductor Product Specification [ ... ]

2SA1021 PDF Datasheet Download