Only 92mm wide. The Mini has a single bright LED in the little housing at the top, and the rest is reflector. The LED glows red, of course. The taillight wire ends must have the little 2.8mm female connectors, which we sell. The mounting bolts aren't electrically grounded, so you must use a 2 conductor wire, but it means it's impossible to create a short. Let us know how long you need the taillight wire to be. We'll make sure you have the right connectors. You cannot wire this taillight without the proper connectors. There's no way to attach bare wires to this taillight.
No button to shut off the standlight. That helps keep the price low. Also, it works with any 6 volt Busch & Müller headlight, including the Luxos U.