ZFE Mix Grit Cylinder Nylon Polishing Buff Burr For Proxxon Dremel Rotary tools Pack of 5Pcs Ideal for polishing&Sanding Metals Surfaces (e.g.: Steel, Aluminum, Zinc alloy, Brass, Copper, etc.) Suitable for the polishing of metal and non-metallic surface especially Precious metals. Perfect Accessories for Jewelers, Coin Collectors, Students, Hobbiest ect. Each brush is approximately 12 mm in diameter and is mounted to a 1/8" (3mm) diameter mandrel Can be used with most multi-function tools, such as for Dremel, Proxxon and many other manufacturers.