These quality All-Purpose nylon brushes are safe for everyday use and are recommended for use on virtually any surface, including wood. The double ends allow for specific cleaning, with the large end allowing for greater surface scrubbing while the small end allows for precision cleaning. They're great for gun cleaning, and are recommended for removing fresh carbon and powder residue, but won't scratch for firearm finish and meets Mil. Spec. The All-Purpose Nylon brushes also work well for automotive, hobby, jewelry, and household cleaning. Also included in this pack is a bonus Blue Nylon All-Purpose brush, with stiffer bristles designed for an even more aggressive clean.