Measures Magnetic Field, Electric Field and Radio Frequency Strength The EMF450 is a convenient 3-in-1 EMF meter which simultaneously measures and displays Magnetic Field, Electric Field and Radio Frequency Strength. Ergonomic pocket-sized design with an easy-to-navigate menu. Large vivid color TFT display shows digital readings, bargraphs, and trending graph. Magnetic Field, Electric Field, and Radio Frequency (RF) Strength merasurements. Store up to 20 RF historical records. Data Hold and Auto Power Off with disable feature. Complete with 3 AAA batteries and USB power supply cable.