Double test function: The EMF meter can accurately detect and measure electric field radiation and magnetic field emission at the same time. It can also measure the ambient temperature. Dual audible and visual alarm: When the tested value exceeds the preset alarm value, it will immediately emit a sound and light alarm signal. Wide detection frequency and measurement range: 20Hz ~ 300Hz magnetic field and 20Hz ~ 3500MHz electric field of the working frequency range; Magnetic field 0.01~199.9T (0.1~1999mG) and electric field 0~1999V/m measurement range. User-friendly design: Soft control buttons for alarm value setting, MAX/AVG value switching and unit conversion, the mini pocket EMF tester is powered by 3 AAA batteries, which makes it convenient to use and carry. High accuracy and sensitivity: Reliable for measuring electric and magnetic field radiation from cellphone, hair dryer, computer, TV, printer, cash register, refrigerator, etc.Package Includes: 1pc Electromagnetic Field Detector Notes:1. Due to manual measurement, please allow 1-3 cm error. Make sure you don't mind before you bid.2.Colors may vary due to different monitors, please understand. Thank you for your support :)