What is the name of the thing that Hong Kong Feng Shui masters use to look at graves?

Hong Kong is called Luo Geng, and we are called Compass. . .

That is, the compass or compass is in the middle and the periphery is in all directions and branches. If it's more complicated, add 28 stars or something. . .

But I personally feel that the role of these is. . . Um ... . Can give people some convenience? . .

But if you really learn Feng Shui, the first lesson is to remember these directions or judgment marks. Which inland true feng shui master needs a compass to see feng shui? At most, he has a compass in his bag for fear of being found. . .

Moreover, I think that people who even have to look at the compass to find directions are really qualified to do Feng Shui?