If it's aluminum, especially white or blue, it's a version 2. Some have the blue lcd controller and others have a rotary controller - I'd get the lcd as it has automatic altitude fuel adjustment while the rotary control doesn't. A couple things to remember when installing them. They don't like air in the fuel lines so if you are going to use a jerry can with a hose through the lid, consider adding a valve to prevent the diesel in the fuel line from draining. Also make sure they get enough power, most reliability issues come from not enough volts to the glow plug. Run bigger wires than the factory wire loom especially if the heater will be located very far from the battery. Somebody else would know more about the feasibility of this than I do, but it might be worth thinking about using a boost converter to get up to 14 or so volts even when the vehicle is off.
