Durable Material: Made of corundum, high quality, durable, long service life, the blade sharpener can be used repeatedly Universal Size - 55 x 50mm for each. Small enough to fit in tight spaces and sturdy enough to sharpen your blades. 1/4" shank fits all power drills Efficient Sharpening: The lawnmower blade sharpener can simply be attached to a power drill and sharpen the blade easily and quickly without gouges or unevenness. Save time and effort Lawn Mower Blade Balancer - 60 x 50mm. Quickly test the balance of the lawn mower. You can choose different diameter steps on the cutter holder for balance test, according to different cutting diameter Wide application: used for sharpening lawn blades, lawn tractors, drill blades, lawn mowers, lawn mowers, tillers, hoes, etc How to use: Step 1: Prepare the blade sharpener and any drill. Step 2: Insert the blade sharpener into the drill. Step 3: Place the knife between the sharpeners. Step 4: Start the drill switch and start sharpening the