Measures board metric units (BMU) of 1000 square centimeters as defined by the National Hardwood Lumber Association. A 4-line ruler, it measures lengths of 3.0, 3.6, 4.2, and 4.8 meters on one side and 2.7, 3.3, 3.9, and 4.5 on the other. A centimeter scale is integrated along one edge and the head is stainless steel marked for metric thicknesses.