Mud should be a vermicelli horizontal pot. The tea stains on it are too dirty and can be cleaned. The teapot doesn't mean how many tea stains are wrapped outside. This in turn affects the permeability of purple sand.

The bottom width seal of the work is "Yixing, China". Generally, artists who are slightly famous will sign their own personal seals. This kind of seal is generally a commodity pot, and the market price is relatively low.