Short description of Perfect Screen Ruler 3.0: How to find out the size of something on the screen or to take a closer look at it? Use Perfect Screen Ruler. You will easily find out the size of any item on the screen, for instance, the size of a button or the distance between two points. You will be able to enlarge the image if necessary. It is useful when you measure some small images or when you need to study the enlarged area of the screen in detail. A color picker is added.