The Spear and Jackson Ready to Use Spray and Leave is ideal for paths, patios, driveways, steps, headstones, garden ornaments and much more. This product is designed to clean mould, algae and everyday dirt away from the affected areas and to destroy the spores which are produced by algae. This will help lengthen the time in which the algae reforms. The formula is designed to work with the outdoor elements, including wind and rain, to gradually wash away the contamination over a number of months - and can continue working for up to a year, depending on the extent of contamination. NOTE: The colour of the bottle may vary