Forever White Grout Reviver is the easy way to restore discoloured and dirty grout to a bright white finish. Simply apply to grout lines using the easy to use applicator, allow to dry and remove any excess residue with a damp cloth. Mould Shield‚ actively prevents the growth of bacteria, mildew and black mould that are commonly found in areas of high humidity. Depending upon size of tile, will cover approx. 20m squared of tiles.