1.Both faces natural Thickness 10-20mm 15-25mmDimension(cm) 30x15 30x30 40x40 20x40 30x60 60x602.One face natural & one face cialliberatedThickness 10 or 15mmDimension(cm) 30x15 30x30 40x40 20x40 30x60 60x603.One face calliberated & one face honed