v2 has two LEDs, a red and a green. One indicates power, the other indicates data. I think that is the only difference. I use both and I also have some V2 that I left the LEDs off. When used in an SSR4, the LEDs sometimes will put just enough power draw on the transformer to give a problem. Does not happen with an LE. Since they are in the case and I normally cannot see them the LEDs, they have not been much use to me other than when I first built them. I have both V1.2 and V2 and have swapped them around with no changes to anything. If you need the connectors that go on the LEs I have some extras of those that I can supply.