4-Piece Scratch Brush Pen Set - Includes fiberglass bristle scratch pen, brass scratch brush pen, steel scratch pen, and nylon bristle scratch pen for various cleaning and detailing tasks. Durable & Insulated Design - The fiberglass scratch brush pen and nylon bristle scratch pen are corrosion-resistant, while the steel scratch pen and brass scratch brush pen provide strong scrubbing power for tougher cleaning jobs.