Incra Rules Stainless Steel 12" Precision Marking RuleDetails: Incra Precision Marking Rules. At first glance you might think you are looking at an ordinary ruler. But look closer and you will see micro fine marking holes and slots every 1 16", 1 32" and 1 64" to instantly locate a sharp pencil point or scribe EXACTLY where you want it. No more squinting as you try to line up your pencil on that blur of lines along the edge of your old steel rule. Even when the lighting is less than perfect, you can