This 3-piece set brushes can handle virtually any cleaning job-There's a nylon brush for delicate and engraved parts, a phosphor bronze brush for aggressive cleaning of blued steel, and a stainless steel brush for the heavy jobs, such as the breech/bolt area. Highlights: Stainless Steel bush for aggressive cleaning of non-blued surfaces Phosphor Bronze for heavily-used blued metals Nylon for delicate parts and wooden surfaces-great for checkering and other carved parts Mfg: Outers