Stole this from another thread.
The one labeled STOP can be used as a constant 12v source.
The highlighted one labeled DRL (daytime running lights) is ignition switched. Keep in mind if you use a add-a-circuit type tap you can no longer put the fuse box cover back on.
As for the fuse tap I don't know what type it was but any AMP/mini fuse tap would work. I got a couple from Autozone.
I ordered the Greddy Multi-D/A and should have it in a couple weeks and will do the install. My guess is I'll just have to use a tap on one of the Illumination+ wires so the gauge turns on with the lights. Otherwise I could just use another 12v ignition source and leave it illuminated all the time. I wish there was a way to make it work with the dimmer switch but the wiring for that is a bit funky and wouldn't really work without cracking open the gauge.