What I have is a complete dash unit like what my old speedo was. It has oil pressure, turn signals, neutral, speed, rpm and whatever else the particular unit offers. The one I got hooked right up to the same wires that activated the oil pressure, turn signals, neutral, high beam etc. My old speedo was a cable driven so I had to add the magnetic pickup to the front wheel (which they have) to make it work. I think the 3900 series units will use the factory installed gearbox pickups that come in most all bikes now. You will have to do some wiring so if that is not your cup of tea be warned! My old cable unit was 10% wrong on speed is what got me to upgrade to digital. I have bought parts from the site quadtech.co.uk with good luck. The fact they are in Britain in today's world is no setback at all. Had good luck with them. If you can't identify your wires then look for a repair manual with a wiring diagram in it. I will give you all the info you need.