Sharpen your chain saw correctly the first time, and every time, with the Sportsman Earth Series Bar Mount Chain Saw Manual Sharpener Filing Guide. All measurements are dial-set and then locked in, removing the irritation of trying to figure it out. Once all the angles, depths, and file heights are set, each tooth on the chain is sharpened the exactly as the one before, for precise and accurate filing. Works with most chain saws, but the round file must be purchased separately.