The hairy belly is the rumen, which is the largest of the four stomachs of cattle, and one side is rough like a towel; The belly is a valve stomach. The beef tripe is the digestive organ of cattle, and the louver is the food storage room. There are many small protrusions on both sides of the louver, like small thorns, and the hairy belly looks smooth; Venetian blinds is thinner and hairy belly is thicker.