SUITABLE TYPE: 18 pieces of diamond drill bits in 3 sizes.5/32'' wheels for Electric chain saw and other small blade, 3/16'' wheels for small oil chain saw, 7/32'' wheels for large oil chain saw. DURABLE :Our diamond wheels are made of emery, and it is titanium platedwhich is durable and sturdy to use. EASY TO USE: These bits are specially designed for Electric Chainsaw Sharpener. Only 2 steps to replace. This titanium-coated file is harder and more wear-resistant, so you don t have to change it often. POWERFUL TOOLS: Because its surface particles are evenly distributed, its grinding performance is excellent. So you can finish grinding things as fast as you can, and get rid of the troublesome hand mill. WIDE APPLICATION:You can use it in metal polishing, chain saws,.it is also suitable for high-precision work, and can be used for cutting or shaping wood and jade.