Green Chloride Grinder(size 70mm): Suitable for grinding carbide, optical glass, ceramics, and other hard and brittle materials. Brown Corundum Grinder (size 70mm): Suitable for high-strength metal, such as carbon steel, alloy steel, forging iron, hard bronze, etc. Easy to Install, Mount the grinder on a conversion rod and then connect it to an electric drill to make grinding more convenient and quick. Fix it on a tabletop with the fixed bracket, which provides better comfort and reduces fatiguefor professional cutting and grinding applications. These tools turn your corded and cordless drill into a grinderfor preconditioning, grinding, sharpening, and removing rust. Easily polish all kinds of knives, metals, handicrafts, jade, scissors, drill bits, chisels, etc., restore their sharpness and color. Compatibility, It is suitable for lithium electric drills and AC electric drills, but NOTfor an electric mill, electric hammer, electric wrench, impact drill., Weight: 1.18608696956 Pounds, Manufacturer: BOFRHME