Suitable for your DREMEL / FOREDOM machine tools. * Ideal for polishing metals surfaces (e.g.: steel, aluminum, zinc alloy, brass, copper, etc.), especially precious metals. * Perfect accessories for jewelers, coin collectors, students, hobbyists etc. * Each brush is approximately 5/8" (16 mm) in diameter and is mounted to a 3/32" (2.35 mm) diameter mandrel.