With this unique tool you can quickly an acurately scribe metal and plastics without measuring. Simply determine the distance required and draw the scribe along the edge . Very simple to use and very accurate..........Scribes edges 1/8", 3/16", 5/16" , 3/8", 1/2", 5/8", 3/4"................ Magnetic back attatches to tool box...................This tool is made in the USA