It is an unsaturated polyester putty, which has the advantages of wide application range, high cost performance, good scraping and easy polishing. It can be used to fill and modify defects such as pits, needle shrinkage holes, cracks, and small welds in the substrate. After hardening and polishing,the surface of the substrate can become flat and smooth. It can be used in the repair process of automobiles, trucks, machine tools, and machinery, as well as in furniture and decoration.