Easily measure just about anything with the Rollova Digital Rolling Ruler. This incredible ruler can measure a wide range of surfaces, objects, and materials with a single motion. By simply rolling the device, ROLLOVA gives you an extremely accurate measurement right on the screen. You can finally take the guesswork and confusing calculations out of measuring everything from flat surfaces to curved objects and more. The Rollova is also compatible with major units of length. Additionally, the digital OLED screen..