If you are tired of buying new bars and chains for your saw, the Felled Chainsaw Bar Sharpener will make your bars last longer. It removes burrs from the bar rails and levels the bar rail to reduce rail chipping while preventing your bar from knifing. This chain saw sharpener bar dresser removes normal wear and minor damage as it dresses your bar rail back to a 90-degree square edge, allowing for longer chain life, better chain lubrication, more precise cutting, and increased safety. Run the file perpendicularly to the bar and use in various positions with the file dressing the outer edges or the tops of the rails. This package includes (1) chainsaw bar file handle and (1) file blade is approximately 4 x 1/8 x 7/8 inch to universally recondition all saw bar rails. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.