Focomat height indicator CKROO -- what is it?

I've just purchased a Leitz Focomat 1C Color enlarger that comes with a "height indicator" -- seems to be a device, perhaps with a bulb in it, that is attached to the base and has a piece that attaches up to the parallelogram of the enlarger head. This may be something called "CKROO" in the Leica product code lingo.

OK, I get that in some manner it indicates how high the head is raised, or how high it is above the baseboard (?). Can anyone shed some light on what this is, and how it works?

Do you have this link to the 2C manual? It mentions it, but not in much detail. In that manual it is called an Enlargement Indicator and it has a bulb to see it in the dark.

My guess is that the indicator is a 'mechanical computer' that takes in to account both the column position and the parallelogram position (and possibly lens selection) to indicate the enlargement ratio. http://manuelsphoto.free.fr/leitz_focomat2c_instructionsforuse.pdf

Yes, ic-racer, I'd seen that passing reference in the 2C manual. Perhaps I'll just have to wait until I get the enlarger, see what it does, and report here.