This part is a kind of semiconductor called MRF455.

Function of this product has RF POWER TRANSISTOR NPN SILICON.

Manufacturers : Motorola

Image and pinout :

Some of the text within the PDF file :

MOTOROLA The RF Line SEMICONDUCTOR TECHNICAL DATA Order this document by MRF455/D 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 Motorola 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 [ ... ]

MRF455 PDF Datasheet Download