Tried searching, but I didn't come up with much useful information on the subject.
I have a Durst m670 BW, which I now (thanks to good helpers on and off APUG ) have both lens and condensers and negative carriers for, to go from 35mm, to 6*6 to 6*7.

All is dandy, really, but I have a question about the numbers on the column scale on the enlarger and how to interpret them.

This is how it looks:

f50 f105 and f80 are easy, these point to the lens used.

I assume that the numbers inside the squares are some kind of enlargement factor? (if so, compared to what really, what do they mean in every day printing?)
There are also numbers to the left and to the right of the squares (inches/cm?), do they just indicate the enlarger head height, or do they give away more information than that?

If someone knows, please enlighten me, I didn't get the manual with this enlarger :/

Printing is going very well though, but understanding these numbers may make it even easier to work in the dark ^^