Calcium, Lime and Rust Stain Remover is a concentrated acid formula that instantly removes calcium deposits, limescale and rust stains. This concentrated formula can be used on brick, stucco, cement, porcelain, glass, and fiberglass to remove stains and discoloration. The cleaning liquid works as a toilet cleaner and is applicable on tubs and sinks. | Zep Concentrated Calcium, Lime and Rust | Size 32 oz