An Iwasaki file cuts fast and leaves an amazingly smooth surface, because its teeth are sharp and cut rather than rip like most files. Unlike a normal wood file or rasp, this file requires little in the way of cleaning, but when it does Mr. Iwasaki recommends this brush. The plastic bristles are stiff enough to clean but soft enough not to dull the files. The Brush is 8-5/8" long with a curved head measuring 3" long by 1/8" wide.