Electromagnetic fields (EMF) emissions are created whenever electrical power flows through a wire, conductor or appliance, they cannot be seen, felt or heard, but they are present in around all electric lines devices. EMF emissions are measured in units called Millguass(mG). This tool can help you to underst the environment fully. If you are looking for this tool, just have a try! Features: Portable Size: The small size of this tool is very convenient for everyday use, you can hold it to use easily. 8and1 LED lights for you to read the testing results the power on/off in the dark in the sunlight. The special function 9-led indicators represent different radiation values, the green lights mean "normal zone" "low zone", the yellow lights mean "caution zone", the orange lights mean "high zone" the red lights means "warning zone". Wide Applications: This tool can be used in your home, electric appliance such as computers, TV, hair dryer, cleaner other devices. Flowmeters are often used for safety to identify potentially harmful high EMF radiation. This tool can help you to underst the environment fully. Specifications: Material: ABS Color: black Power: 1 9V battery (NOT INCLUDED) Item size: 190 45 27mm / 7.5 1.8 1.1in Item weight: 82g / 2.9ounce Package size: 190 135 105mm / 7.5 5.3 4.1in Package weight: 178g / 6.3ounce Packing List: 1 EMF Meter 1 User Manual