The STIHL Guide Bar Dressing Tool is designed to maintain all your STIHL guide bars by removing burrs from guide bar rails, leveling the guide bar rails and preventing the guide bar rails from knifing. The included file is constructed from high-grade steel and is pre-oiled for resistance to rust. The handle resists rust and corrosion and is constructed from hard plastic for maximum strength and longevity. This maintenance tool removes normal wear and minor damage as it dresses your bar rails back to a 90-degree square edge. Redress your STIHL chain saw guide bar rails to 90 degrees to keep the saw chain cutting straight.