5 1/4 inches long. Very old. A beautiful brass example of the traditional Japanese ink line, or sumitsubo, a tool believed to date back to ancient Egypt and China. The sumitsubo is an important spiritual symbol, so the early custom was to leave it in the newly built shrine or temple as a treasure. In modern times, it is given to the master carpenter, who will likely donate it to the shrine. This tool is used to mark wood where it is to be cut, much like the Western chalk line. Its ample well was made to hold a wad of silk cotton saturated with ink. When the line is drawn through, it picks up the ink for marking.