MARSHALLTOWN The Premier Line 840 6-Inch by 3-Inch 20-Grit Rub Brick
Marshalltown 16440 6 X 3 X 1 20-Grit Rub Brick is made of fluted silicon carbide stone, that's  20-grit. This rub brick is ideal for dressing down and removing form marks from concrete, or for smoothing and dressing down wet tile. It features a securely attached comfortable handle.