The twin-use scale lets you measure and plot in both metric and imperial measurements. It features a bevelled edge that provides increased accuracy when measuring by shortening the distance between scale and paper. Sturdy acrylic provides durability for frequent use. Ruler for general document measurements. Measure from 0 mm to 150 mm (0 inch to 6 inch) With metric and imperial scales Bevelled edge provides increased accuracy Sturdy acrylic construction