Trifield 100XE 60Hz - With Sound Detects 3 type of EMF pollution: AC magnetic fields, AC electric fields, radio/microwaves. Two magnetic ranges cover 0.2-100 milligauss. Electric range covers 5-1000 V/m (or .5-100 kV/m with original version of the Trifield Meter) Operates about 40 hours on replaceable standard 9V battery, has a low battery indicator. Radio/microwave covers 0.01 to 1 kV/m (kilovolts/meter) This corresponds to 0.026 to 266 mW/cm2.