It is made of "Mount Taishan Green" granite by mechanical processing and manual polishing. Black luster, precise structure, uniform texture, and good stability. High strength and hardness. And it has the advantages of non rusting, acid and alkali resistance, non magnetization, invariance, and good wear resistance. Can maintain stability under heavy loads and normal temperatures.Granite platform It is a precision reference measuring tool made of stone material, which is an ideal reference surface for the inspection of instruments, precision tools, and mechanical parts.