Features 1、WORKING PRINCIPLE: Used to measure the electromagnetic field to identify the equipment that produces high radiation, respond EMF fluctuations and spikes immediately. 2、5 INDICATOR LIGHT: The detector has 5 lights to indicate different radiation values, dark green 0 to 1.5mG, green 1.5 to 2.5mG, yellow 2.5 to 10mG, orange 10 to 20mG, red 20+mG. 3、MEASURING RANGE: Various EMFs from 50Hz to 20000Hz can be measured, the EMF level can be measured to prevent the equipment from potentially long term overexposure to EMF. 4、PORTABLE DESIGN: The radiation tester has a compact size, portable design, easy to use and carry, and can be used after opening the switch, sensitive, stable and reliable. 5、PLASTIC HOUSING: The magnetic field detector shell is made of excellent ABS, with good toughness, corrosion and aging resistance, and can be used in various environments. Specification Item Type: Radiation Tester Material: ABS Accuracy: 5% Product Size: Approx. 143 x 53 x 29mm / 5.6 x 2.1 x 1.1in Detection Range: 0 to 20+ mG Detection Frequency: 50/60Hz (50 to 1000Hz ELF, 1000 to 20000HZ VLF) Battery: 1 x 9V 6F22 battery 800MAH (built in battery) Use: Used for individual security to identify potentially harmful high EMF radiation. It is an excellent tool to detect mental activities and detect potentially harmful high EMF levels in the family or work environment. Package List 1 x Radiation Tester 1 x User Manual