The image shows an Extech EMF510 EMF/ELF Meter, a handheld digital device used to measure extremely low frequency (ELF) electromagnetic fields (EMF).Measurement Range: 0 to 2000 mG (milliGauss) with a single-axis sensor.Frequency Response: 30 Hz to 300 Hz, making it suitable for checking power lines, home appliances, and electrical circuits.Key Features: Includes a backlit LCD screen, Data Hold, Min/Max recording, and Auto Power Off.