Copper cartridge. There are white copper, brass, red copper, etc. Among them, the white copper ink cartridge is the best. The seventh-grade official ear is the seal used by Zheng Banqiao. It is rare to be confused. For the rest, just search {Copper Ink Cartridge} on Baidu. There are many prices, pictures, etc. for reference. ?It is estimated to be new. Zheng Banqiao is an official after all, and he does not know how to use brass inkstones. The market price for corrosion is 100-200, and for engraving is 300-500.