What is the etalon installed in Longlin?

Long Lin costume is a kind of traditional armor equipment in ancient China, which was used to protect soldiers' physical safety in battle. The standard instrument of Longlin is Longlin ruler, also known as Longlin ruler. It is a tool for measuring the size and arrangement of Longlin to ensure that the production of Longlin clothes meets the standards. Longlin ruler is made of wood or metal and has a specific size and scale. Used to measure the length, width and spacing of Longlin to ensure the quality and consistency of the equipment.