Feature: 1. Wide Application: The EMF meter detection helps to measure electromagnetic fields, identify equipment that generates high radiation. The EMF tester is mainly used for testing televisions, computers, microwaves, refrigerators, printers, cellular towers, low frequency appliances, etc. 2. Colorful LED Indicator Lights: This magnetic field detector has 5pcs LED indicator light that can be seen reading during the day or in the dark, as it can be placed in your pocket or wallet, making it easy to carry with you. 3. Easier Detection: The level of the EMF radiation detector is measured to prevent potential effects from long term overexposure to electromagnetic fields. You can use this detector at home, office, and other places. 4. Accurate Measurement: The EMF detector operates on a single battery and reports the EMF measurement results within the range of 5 mGyS. 5. Wide Frequency Range: This electromagnetic radiation tester used for radiation measures various electromagnetic fields from 50 Hz to 20000 Hz, and can detect mobile phones within 2 feet. Specification: Item Type: EMF Meter Material: ABS Battery: 1 x 9V battery with 800mAh capacity, shipped with built in battery. Detection Range: 0-20+ milliGauss Detection Frequency: 50/60Hz, 50-1000Hz for ELF, 1000-20000Hz for VLF. . Package List: 1 x EMF Meter1 x User Manual Note: The battery needs to be replaced when it runs out of charge, and the detector cannot be charged. Firstly, use a screwdriver to unscrew the plastic cover. Then remove the battery, and finally just insert a new battery and tighten it again with a screwdriver.