B5 multi-function underlay with ruler and full circle protractor... Angles can be measured with a full circle protractor. Memory is marked every 10 degrees at the edge of the underlayment, so it is easy to measure the angle of large buildings and scenes. The ruler scale is also color coded in black and white, so you can use it according to the color of the object. Size: Height 9.8 inches (250 mm), Width 7.1 inches (180 mm). Product Color Trend:Clear.