The black metal box is in the shape of a cube, about one foot in length, width and height, and the same body is black, with traces of time left in a few places.

"Yo? You have a good eye." The old man walked over, picked up the box gently, put it on the front side, and said, "This black metal box is from the Song Dynasty. It has been authenticated and has all the certificates. It is genuine. It sells for three hundred yuan. 800,000. Its function is to collect some collections of high-ranking officials and nobles in ancient times. There are square grooves in it. Unfortunately, the things inside are not there. I put another set of metal cards in it. It fits well, so these two sets together For sale, the total price is 3.98 million."

The old man opened the box while he was speaking. The inside was the same as an ordinary box, with downward grooves, and there were small square grooves on the ground floor, with a total of eighteen black and gold cards on it.