The Stanley Intelli Tools IntelliMeasure® Distance Estimator can measure length, area and volume. It has a large, easy-to-read LCD screen that shows either metric or imperial measurements. It can also display the last three measurements for quick reference. The intuitively designed toggle button lets you effortlessly switch between length, area and volume measuring modes. It will automatically calculates area and volume. There is also a manual addition mode for specialised calculations (i.e., perimeter). Specification Accuracy: ±5mm.Operating Range: 12m (40ft).Power Supply: 1 ;x 9 Volt ;Battery (NOT Included).