Power Source Battery Powered Item Weight 3.78 Ounces Battery Description AAA_(Micro) Frequency 3500 MHz Number of Batteries 3A - Included ) About this item EMF MeterThis EMF detector with two uses, it can test electric field and magnetic field radiation at the same time.(1V/m and 1999V/M) Precise Data StorageOne Key Lock Radiation (Hold - Beep); It Was Equipped With Built-in Electromagnetic Radiation Sensor, Which Can Display The Radiation Value On The Clear LCD Digital Screen After Microchip Control Processing Automatically AlarmThe Instrument Will Automatically Alarm (Electrical Field Boundaries 40V/m, Magnetic Field 0.4't). Built-in Fast Signal Strength Speaker (Fast Tone Size is Proportional to Electromagnetic Field Strength), Effectively Help Identify Signal Source and Locate Signal Position Quickly Product AdvantagesThe Radiation Assessment Would Remind You Whether The Radiation Value Is Safe Or Not, High Sensitivity, Light Weight, Easy One-handed Operation, Automatic Display, Easy To Carry Or Field Measurement, Energy Saving And Environmental Protection, High Threshold Historical Data Storage Range of ApplicationWith Slim Easy EMF Protection Anti Radiation Sticker: Protect Against Cellular Radiation and Immune Pollutants. It Can Be Used On Any Device Larger Than A Cell Phone. Desktop Computers, Laptops, Kindles, iPads, Mobile Phones, Handheld Devices, Microwave Ovens, Refrigerators, Gaming Devices, Televisions, and Miscellaneous Household Appliances Using Rechargeable Lithium-ion Batteries