Sharpening chainsaw chains with a round file takes time and can only be done when the file is used correctly you will do it easier faster and preciser when you use this new forstmeister chainsaw sharpener with this sharpener from westfalia you can sharpen most common chainsaw chains precisely and easily further advantages of the sharpener the illumination transparent glass so you can see what you are doing pivoted grinding head scale so you can set the grinding grade precisely