To prevent the lack of mask, just replace the sheet when it gets dirty, so the mask will last longer.If you cut 1 to 4 pieces, you can use it as is without cutting it to 100 pieces. 3.3 x 4.9 inches (83 x 125 mm) (Unfolded 7.3 x 9.8 inches (185 x 250 mm) 25 pieces *Please note that this is not a mask.