It is probably a Ray Type II. It may be a Type I, the smaller. These are bullet proof drives as long as you keep them dry and grease the hell out of the chain (motor cycle drive chain). Mine has about ten years on it with no trouble. There are four wires to the drive motor. The heavy two are for power and the light ones for the clutch. A trick I learned a long time ago was to put a switch in one of the clutch wires as an emergency disconnect. This allows you to take control by hand very fast. It would only be necessary if the control head isn't where it can be reached quickly.