INCRA scores again with its precision steel rule! Select the proper slot or hole, insert a .5mm mechanical pencil, and mark the measurement with dead-on accuracy. The TRULE18 Marking T-Rule offers Incra's patented marking holes at every 1/16, 1/32 and 1/64 inch from 0 to 18 inches. It also offers 0 to 3" height markings on the end in 32nds. It is made of high-quality steel, making it extremely durable. These marking rules are fast and easy to use. They also provide an incredibly accurate method of measuring.