Easy to operate and move, convenient for on-site measurement, and effective identification of magnetic field source and electric field source. Equipped with high quality built-in electromagnetic radiation sensor and , making the test results more accurate. Automatic audible and visual alarm. When the test exceeds (electric field 40 V/M, magnetic field 0.4 or 4mG), the audible and visual alarm of the electromotive force tester will be triggered. Press and hold the middle button to turn the audible alarm on/off. size backlit LCD for easy reading, rechargeable batteries, average and reading, data retention, two cell , and temperature measurement. Power off automatically after 5 minutes without operation It can be used to test PC, laptop, TV, mobile phone, oven, refrigerator, telephone, WIFI router, mobile phone tower and household appliances Electric field: Range: 1V/m-1999V/m Alarm : 40V/m Resolution: 1V/m Magnetic field: Range: 0.01T-99.99T / 0.1 mG - 999.99 mG Alarm : 0.4T / 4mG Resolution: 0.01T / 0.1 mG Temperature: Resolution: 0.1/ Colour: Black : plastic Package Contents: 1 x EMF Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.