Swauber Applicators are a must have for any shop toolbox or workbench. Use them for applying gun blue chemicals such as plum brown , perma blue gun blue and super blue gun blue. Or, use them to apply any firearm cleaning products such as Bore Scrubber 2-in1 bore cleaner, Barricade protectant and Rig Rust protectant. Any job that requires the application of a liquid product, the Swauber is the right tool for the job!