Convex mirror, hanging in the living room, facing my stairs.
In geomantic omen, mirrors are often used to ward off evil spirits, and some people use them as tools to dispel evil spirits, so they should not be used casually. There are many kinds of mirrors, such as concave lenses. Convex lens, eight diagrams mirror, flat mirror, white tiger mirror, etc. These mirrors are mainly used to make and illuminate evil spirits, which means hanging divination. They embody the direct ShaQi, or make it invisible to avoid being damaged by it. These should be used under the guidance of professional teachers.