Effectively cleans .380 cal., 9mm, .38 cal., and .357 Mag. Firearms in one pass. Heat resistant (up to 700F) Nomex synthetic fiber construction. Acts as both a brush to loosen and a patch to capture fouling products. Molded rubberized core keeps the cleaning surface pressed against the bore. Coated solid brass threaded ends won't scratch or damage bore. Safe for all firearms.