MMR PLUS is a heavy-duty commercial concentrated mold & mildew stain remover that is specially formulated with additives and sodium hypochlorite to remove the toughest mold and mildew stains from building surfaces such as concrete, wood, blocks, and vinyl siding. Spray on and watch the stains disappear. Product has low levels of foam for enhanced cleaning. Where other stain removers fail, MMR Plus doesn’t.