EM4558 is a device that measures the magnetic field emitted from surrounding devices. It is equipped with a built-in electromagnetic radiation sensor, which displays radiation values on the test indicator LED. Electromagnetic wave intensity: level 5, level 1-5 (easy to read, fast response multi-segment LED display) Check the strength of electromagnetic waves around devices that are subject to electronic wave interference. Help find seats with low electromagnetic intensity caused by motors or transformer, which can be ignored when you take high-speed trains or other vehicles. Check the intensity of electromagnetic waves around the living environment or transmitter. (you can use the tester to check PC, radio, mobile phone, blower, refrigerator, electric oven, rice cooker, computer room, control room, signal tower, copier, fax machine, microwave oven, air conditioner, etc.) Features: portable design,EMF sensors,LED test indicators, structure and operation, Manufacturer: MOOILKO