Features: Excellent design for a measurement of electromagnetic field radiation levels around power lines, home appliances and industrial devices. Used widely in electrical equipment, electromagnetic radiation measurement, phones, computers, TV set copy machine, fax machine, AC, refrigerator and so on. Suitable for most measuring effects of radiation products, presentations, and personal understanding of radiation. Designed to meet CE. Simple operation, highly sensitive, and 50Hz-2000MHz frequency range. Accurate and safety to use. Portable and stable. Specifications: Material: Plastic Color: Black Screen: LCD Frequency Range: 50Hz-2000MHz Reacting Time: 0.4S Voltage: 9V Battery Model: 6F22 9V(Battery is NOT included) Size: 132MMx69MMx29MM/5.20 x 2.72 x1.14Inch Weight: 157G Package includes: 1 x Electromagnetic Radiation Detector How to detect: Switch on the device. Close to the object slowly until contact it. The closer the distance is, the stronger power of electromagnetic radiation is. Remind: Do not close to the object with high voltage. Change the angle during detecting until get the maximum data. When the object is power off, the reading will be restored to 0 unless there are other electromagnetic radiation disturbings. About battery When the reading of the device is too low or no alarm that means low power, please change battery. Please remove the battery when finish using it.