DIAMOND MATERIAL: These diamond needle files are made of high quality metal, solid, compact and durable for a variety of polishing, with excellent workmanship, bringing fast cutting and high efficiency. EQUIPPED NON-SLIP HANDLE: This diamond needle file is equipped with a non-slip handle with a comfortable grip. Each part of the polishing file is covered with soft plastic, which is comfortable to grip and non-slip. WEAR AND CORROSION RESISTANCE: These diamond needle files have superior performance in wear resistance, corrosion resistance and high temperature resistance. So it's very safe, you can buy it with confidence. COMPATIBLE USAGE: These diamond needle files are mainly used for super hard, very blunt and serrated knife gripping tools, mainly used for grinding big occasions. And it can meet most people's needs. A PERFECT CHOICE: These diamond needle files are a great choice for fast, safe, and smooth filing and grinding. And it is used in the processing of steel, ceramics, glass, bearings, molds, gears and other parts. Note: The data are all measured manually. Please allow an error of 1-3cm. Due to the difference between light and display, there is a certain color difference, which depends on the actual object received