CLR's Powerful cleaning action; works instantly. The powerful, patented formula takes on tough calcium, lime deposits, scale and rust stains and is safe for various applications. Has unique formulation that cleans multiple items and surfaces including tubs, toilets, sinks, glass, fiberglass, stainless steel, stucco, brick, cement, HVAC, dehumidifiers, humidifiers, swamp coolers, porcelain and more. Many industrial and commercial uses in healthcare, manufacturing, automotive, energy, government and hospitality areas.