The so-called "nozzle" refers to all points on the horizontal contour curve of left sand and right sand flowing out of Luocheng after all the water flows in Tang Ming converge, and the interval between these two tangent points is called the nozzle of the foundation site or cave yard. Generally speaking, it is determined by the tangent point of sand around the farthest outlet in Tang Ming.
There is a famous saying in geomantic omen: "Mountain manages people, water manages wealth". Shuikou is the intersection of local water. The intersection of water is the intersection of wealth.