Drox is a heavy-duty acid cleaner that will remove scale from any surface that is harder than the scale. It is the perfect product for cleaning boilers, water meters, etc.. Drox is also effective on removing welding burn marks from stainless steel, etching concrete, removing concrete from metal equipment such as mixers and forms. May also be used for removing rust from concrete. The first product we started blending, Drox is proudly, still in our product line today. It is a hazardous material and cannot ship by FedEx Express. Contact us for a price and shipping quote.