This part is a kind of semiconductor called 2N6259.
Function of this product has Silicon Power Transistors.
Manufacturers : SavantIC
Image and pinout :
Some of the text within the PDF file :
SavantIC Semiconductor Product Specification Silicon NPN Power Transistors DESCRIPTION ·With TO-3 package ·Low collector saturation voltage ·High power dissipation APPLICATIONS ·Designed for high power audio ,disk head positioners,linear amplifiers,switching regulators solenoid drivers,and DC-DC converters or inverters PINNING PIN 1 2 3 Base Emitter Collector DESCRIPTION 2N6259 Fig.1 simplified outline (TO-3) and symbol Absolute maximum ratings(Ta= ) SYMBOL VCBO VCEO VEBO IC ICM IB IBM PD Tj Tstg PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector current-peak Base current Base current-peak Total Power Dissipation Junction temperature Storage temperature TC=25 CONDITIONS Open emitter Open base Open collect [ ... ]