This part is a kind of semiconductor called BU2508AF.

Function of this product has Silicon NPN Power Transistors.

Manufacturers : Comset Semiconductors

Image and pinout :

Some of the text within the PDF file :

NPN BU2508AF NPN SILICON POWER TRANSISTORS The BU2508AF is silicon power transistor mounted in Jedec TO-3PF plastic package. They are designed for use in horizontal deflection circuits of color TV receivers. Compliance to RoHS. ABSOLUTE MAXIMUM RATINGS Symbol VCES VCEO VEBO IC ICM IB IBM PC TJ Tstg Ratings Collector- Emitter Voltage(VBE= 0) Collector-Emitter Voltage Emitter-Base Voltage Collector Current- Continuous Collector Current-Peak Base Current- Continuous Base Current-Peak Collector Power Dissipation @ TC=25°C Junction Temperature Storage Temperature Range www.DataSheet.net/ Value 1500 700 7.5 8 15 4 6 45 150 -65~150 Unit V V V A A A A W °C °C THERMAL CHARACTERISTICS Symbol Rth j-c Ratings Thermal Resistance,Junction to Case Value 2.5 Unit °C/W 25/10/2012 08/11/2012 [ ... ]

BU2508AF PDF Datasheet Download