It fixes the needed measure on the square or 2nd square.
Useful when you need to make several panels with the same dimensions: just adjust the stop when starting work, then insert the sheets to be cut by pushing them until they reach the stop.
Optional for Ciak Professional and for Ciak Power.
One piece of stop for CIAK Square. Usable on "CIAK squaring kit 60 cm" and on "Ciak second square" tools.
(This is not good for the ruler, but the COPT22STOP.)