Compact and easy to use, this digital unit can measure extremely low frequency (ELF) magnetic fields from 13 Hertz (Hz) to 1 kilohertz (kHz) and/or very low frequency (VLF) magnetic fields from 1 to 75 kHz. This can be done in either single axis mode to help identify the orientation of the field or 3-axis mode which makes routine measurements much faster and more reliable. One knob selects from 3 modes: 3-axis ELF+VLF, 3-axis VLF, 1-axis ELF+VLF. Ranges from 0.01 milli-Gauss (mG) to 1999 mG. Uses a standard 9V battery (included). It is made in the USA with a one-year manufacturer’s warranty.