Luban ruler is mainly used in residential houses, doorways, windowsills, beams, shingles and other construction purposes. It is suitable for measurement in a variety of occasions and industries. Red is good fortune, black is bad For good and bad measurement, Luban ruler tape. According to legend, it was made by Lu Ban during the Spring and Autumn Period and Warring States Period. Later, the eight characters were added by Feng Shui to measure the good or bad of the house Recommended by architects, Manufacturer: qiwangdianzi