With the push of a button, this simple and accurate gaussmeter measures the level of magnetic field emitted by all common electrical appliances, equipment and enexplained distrubances . An easy to read 10 LED light bar scale gives readings from 1.3 to 30 mG in small increments. The ElectroSensor has a detection range of 50-60 Hz. A pickup coil in the tip of the unit can be rotated for increased directionality. If you are looking for a low cost, user-friendly meter, here it is! AAA battery included. We like this better than the K2 meter, and it costs much less!