Cuts vines and grass wrapped around the shaft of a grass trimmer. Reduces tangle of vines and grass for smooth grass trimming. Reduces engine burden and improves workability. New design. 3-sided sharpening blade cuts securely. The 6 blades are alternating high and low for more efficient cutting of grass that is wrapped in. ·This product has been hardened When the blade has become sharp, polish with a diamond file to restore its sharpness. Do not use a grinder, please use a manual file. Re-polishable and long lasting. Outer diameter 5.1 inches (130 mm), blade number 6P, mounting hole diameter 1.0 inches (25.4 mm), thickness 0.04 inches (1.0 mm); Can be mounted on most engine type grass trimmer (lawn mower). Can be used with grass trimmer head (gear case) under 3.1 inches (80 mm).