Prototrak series of Popular XYZ Milling Machine

Why are there so many different variations of this controller that do the same thing!

You would have to ask ProtoTrak engineers that question. All we know is that we have the LCD replacement for this entire series. There are a couple of variations to take note. The MX2 and MX3 Prototrak monitors are different than the M2 and M3 versions. As well the identification number for the controller from the back of the unit is important.