What is this Transistor

What is this transistor? SMD code is Br. this is used in frequency generator output section. If any substitute have this transistor Please help me.

This resembles a microwave transistor I purchased at Radio Shack several years ago. Like your diagram it had four terminals extending outward in a plane, and the narrow legs were different lengths from the other legs.

MRF-901

Cat. no. 276-2044

Thank you Mr.BradtheRad this is a ceramic transistor, but datasheet and photos showing MRF-901 is silicon transistor.

MRF901 transistors come in many different semiconductor packages (see the datasheet).

please, if you can attach all the code lists SMD transistors, ..
example:
J3 =?
2TY=?
431=?
S07=?
etc