LPL VCCE Head Operation

I have VCCE head on my LPL 7451 enlarger and it only has one dial to set the paper grade. So simple even I can work it! Was given a VCCE head for my LPL 7700 chassis (with a colour head) which I decided to fit tonight. I don't have the manual and I can't find one so I'm wondering if anyone can explain setting the paper grade on this thing. How are the "1-2" slider and windows linked. Why do both have 0-5 settings and when you alter one the other alters slightly? Is that working correctly?

P.S. Sorry for the wonky image, taken on my phone and it was a bit dark for it... after all it's a darkroom

Channel 2 is for Ilford papers and channel 1 is for Kodak papers, unless that model was different than their others, which I doubt.

The numbers 0 - 5 are the contrast adjustment, 0 is softest and 5 is hardest. Today the Ilford system is very common, use that setting with Ilford papers, and for other papers unless they specifically state the Kodak system should be used.

thank you... it did not occur to me they were separate channels for the types of paper.