Powerful Hard Water Remover: Takes off calcium hard water spots, rust, lime stains and soap scum. | Works On All Hard Surfaces: Glass, chrome, porcelain, tile, quartz, sealed marble and granite. | Easy: Spray on, wait one minute, wipe or scrub off. Apply twice for the toughest, built-up stains. | Safe: Non-abrasive, acid free and non-etching. | Use On: Shower doors, fixtures, tubs, pool tiles, fou