3M 50079 Trizact Film fine finishing Discs are revolutionary structured abrasives for use in Paint refinishing, i.e. removing dirt inclusions after painting. The discs have pyramid shaped structures which contain multiple layers of fine grade abrasive mineral. As the abrasive wears, sharp mineral is continuously exposed. The result is a consistent smooth finish and exceptional life. The discs are used before compounding. Use after conventional abrasive on larger nibs and alone on small nibs. Although adding an extra step in the process on large nibs the total job time is reduced by an average of 30%.