Neutralizes the acidity of the basic cleaner: Finalit No. 1 Intensive Cleaner (basic): to neutralize the acidic cleaner No. 9.
Pre-treatment for highly absorbent materials: Finalit No. 21S Pores Filler - only necessary before applying Finalit No. 22 if the stone is highly absorbent, e.g. as with concrete stone, limestone, etc.