Alumicolor's Combination Architect and Engineer 4 Bevel Scale is a precision measuring instrument. This 6" scale has Architect calibrations of: (1/8, 1/4), (1/16, 1/32) E: 25, 30, 50, 60 and Engineer calibrations in 10, 20, 30, 50 parts per inch. The beveled edge allows for precise measuring and drawing. All Alumicolor products are made from the highest quality extruded aluminum. The extrusion process creates rulers and scales with smooth edges to exact specifications. The Alumicolor photo anodizing process makes the finish, the color and the calibrations a permanent part of the aluminum. Calibrations are resistant to cleaners or solvents. The anodizing process also means no ticks, raised surfaces or grooves to interfere with the creation of accurate plans, drawings and other precision work.