Th??c l? ban is a free Android application developed by TurkeyGameStudio, categorized under Lifestyle. The app is designed to help users find beautiful numbers for the Lỗ Ban ruler by applying 11 different types of rulers, providing accurate results for the range and radius. The Lỗ Ban ruler is used to measure the size of objects according to 8 good or bad directions (Eight Trigrams). It is applied to measure the size (length, width, height) of objects such as doors, stairs, beds, cabinets, and chairs. The app provides three types of Lỗ Ban rulers, including 52.2cm ruler for non-ventilated areas, 42.9cm ruler for the positive side of the house, and 38.8cm ruler for the negative side of the house. If you are preparing to build a house, close the door or do anything related to the negative side of the house, then choosing the right size to suit Feng Shui is essential.