SB 2101 Heavy Duty Restoration Cleaner is a very highly concentrated blend of acids and other beneficial additives for use in the removal of heavy exterior atmospheric soiling and most stains found on brick, sandstone, fired clay products and unpolished slate and granite. SB 2101 should not be used on marble, limestone, buff colored masonry or concrete products. When diluted with water, this product makes a highly effective, low cost cleaner for the restoration of most exterior masonry surfaces. When