Three types: EMF meters detects three yypes of EMF pollution, AC magnetic, AC electric, and microwave Auto Sound and Tricolor Alarm: Tricolor LCD will turn green, yellow, and red, automatic alarm triggers above the safe value (250 V/m or 5 uT/50 mG or 50 mW/? Easy to Use: Operate with one hand and move or make field measurements(You have to hold the EMF METER to make a test) Mute Function: The device can be muted to prevent scaring ghosts away. or when youre testing some quiet areas, you can turn off the buzzer first, avoid disturbing the others The device features an automatic shutdown after 15 minutes to save battery life. If you need continuous measurement, you can disable the APO function: Press and hold the "APO" button to turn off the auto power-off feature Illuminated Screen: Designed with an illuminated Tri LCD screen to aid ghost hunting in the dark When measuring the electric field, it is essential to hold the device in your hand. This is because the human body acts as a grounding source, ensuring more accurate readings. If the device is placed on a surface, the measurements may be inaccurate due to environmental interference