Professional window cleaners use a variety of tools and solutions to achieve streak-free and spotless windows. One common tool is a squeegee, which is used to remove water and cleaning solution from the glass surface. They also use a scrubber tool, typically a strip washer or microfiber cloth, to apply a soap and water solution and loosen any dirt or grime. Additionally, professional window cleaners may use a proprietary cleaning solution, such as a mixture of distilled water and professional cleansers. These solutions are effective in removing stubborn stains and leaving windows sparkling clean. It’s important to note that the exact tools and solutions used can vary depending on individual preferences and specific cleaning situations.