The Karcher 3-in-1 glass finisher is the easiest way to keep large areas of glass such as patio windows and conservatories looking their best. The Glass finisher uses a protective formula which ensures cleanliness without leaving any spots or streaks. For the best results: 1. Clean the windows or glass surface using the Karcher universal cleaner and a karcher brush. (these can be used in conjunction with a Karcher Pressure Washer) 2. Thoroughly rinse the surface with a pressure washer ensuring that no residual detergent is left behind. 3. Apply the glass finisher by hand and wash off any residue with a pressure washer. 4. Leave the surface to completely dry to ensure a complete coating. The Karcher Glass Finisher should not be used in conjunction with any pre-coated glass.