What is a double-decker feng shui ball?

According to the structure, Feng Shui Ball can be divided into single-layer Feng Shui Ball, double-layer Feng Shui Ball and three-layer Feng Shui Ball. The double-layer feng shui ball you mentioned is one of them. In addition, the sizes of Feng Shui balls are also different, including miniature Feng Shui balls, small Feng Shui balls, medium Feng Shui balls, large Feng Shui balls and giant Feng Shui balls, which can be selected according to the use environment.