You easily measure the length or size of the object by placing it at the screen and adjusting the measuring area tightly.The phone is calibrated already at the factory, but you can also do a calibration yourself by using another ruler, or a suitable object of known size. Key features: Handy ruler, Measures in cm, or inches (decimal or fraction), Just measure anything that fits into the screen, Measures just length, or length and width at the same time, Has a high precision caliper mode for accurate adjustment of the measuring area, The measurements can be stored in a list. A listed measurement can be retrieved back to the screen.