A unique formulation of hydrochloric acid that will remove rust, lime and scale build-up on toilets, humidifiers, water coils, refrigeration units, air conditioners, boilers, lines and valves. It will restore that glossy look to toilets while freeing rim holes, jets and traps of lime and rust. Can be used to clean iron, copper, brass or dissolving concrete. Do not use on chrome, magnesium, aluminum or other soft metals. Santeen toilet bowl cleaner is so concentrated it can be used 1 part to 15 parts of water depending on the strength needed.