Hi,
I don't know if you went to his main website at -
http://www.3dcnc.extra.hu/en/kompas-h-1000-komplet -

They are not ball screws, I think........?

New MDL user adjustable zero-backlash nuts

Modular design from stock components offering a very strong / solid professional machine.... Now with the addition of our user adjustable zero backlash trapezoidal nuts.

Andy.