The Diafold Serrated Knife Sharpener not only maintains serrated edges but also serves as a mini-steel, gut hook sharpener, and conical file. The taper of the sharpener measures 1/4" at its widest point down to 1/16" at its narrowest. Convenient size measures 9 1/2" long when open and 5" when closed. Folding plastic handles protect sharpeners when not in use. Sharpens in a fraction of the time required by conventional stones. No messy oils needed -- sharpen dry or with water.