This part is a kind of semiconductor called MRF455.

Function of this product has RF POWER TRANSISTOR NPN SILICON.

Manufacturers : Tyco Electronics

Image and pinout :

Some of the text within the PDF file :

SEMICONDUCTOR TECHNICAL DATA Order this document by MRF455/D The RF Line NPN Silicon RF Power Transistor . . . designed for power amplifier applications in industrial, commercial and amateur radio equipment to 30 MHz. • Specified 12.5 Volt, 30 MHz Characteristics Output Power = 60 Watts Minimum Gain = 13 dB Efficiency = 55% MATCHING PROCEDURE In the push–pull circuit configuration it is preferred that the transistors are used as matched pairs to obtain optimum performance. The matching procedure used by M/A-COM consists of measuring h FE at the data sheet conditions and color coding the device to predetermined hFE ranges within the normal hFE limits. A color dot is added to the marking on top of the cap. Any two devices with the same color dot can be paired together to form a ma [ ... ]

MRF455 PDF Datasheet Download