Description These are 20 diamond grinding bits, made of safe and durable materials, have a long service life. The surface is covered with a large amount of diamond grit. Good gift for DIY enthusiast hobbyist or craft fan. They are wear- resistant, maintain sharpness, not easy to fall off. Features- Size: 1. 50X1. 50X4. 40cm/ 0. 59X0. 59X1. 73inch.- Color: As shown.- Material: Emery.- Diamond burr bits have different shapes, can meet your different needs.- High- quality materials and good craftsmanship ensure its durability and practicality.- You will receive 20 useful diamond grinding heads, good quality and low price.- Perfect for engraving gemstones, glass, porcelain, tiles, carbide, rocks, ceramics and copper.- Great for crafts, hobbies, home repair, jewelry, lapidary use, modeling, and so much more. Package Including 20 x grinding bits