Material: Made of high-quality corundum, sturdy and durable for a long service life. The sharpening part is quite rough, which makes it easy to sharpen the blade quickly, saving time and effort. Package: 4 pieces of lawn blade sharpener in red + 1 piece balancer. Main Features: This lawn mower knife sharpener can sharpen the knife easily and quickly, which will shorten the sharpening time. It saves time and energy and is a very practical tool in daily life. Easy to use, suitable for most electric drills and hand electric drills, can sharpen the blade easily and quickly. The blade compensation is designed to fit 99% of all holes. central Ideal for sharpening lawnmowers, drill knives, mowers, sickles, tillers, garden tools and art tools, but without serrated blades or ceramic knives