Telemetry LEDs are the addressable lights on sim racing hardware that show live data from your sim. On a DDU or a high end wheel they sit in three runs:

• A centre strip, the rev bar, showing engine revs and your shift point
• A left side and a right side, carrying everything else: flags, the proximity spotter, brake pressure, pit lane, ERS and low fuel

DNR writes that layout as X-N-X, where N is the number of LEDs across the centre. You download the profile whose N matches your device, and the plugin works the sides out from the length of your strip.

Every LED device keeps its own settings, so a wheel, a DDU and a button box can each run a telemetry profile and each do a different job.