Features: Dual Testing Functions: the EMF meter can accurately detect and measure the  electric field and magnetic field emission at the same time. It also can measure the environment temperature(℃/℉). Audible and Visual Dual Alarm: if the tested value exceed the preset alarm value, it will produce sound and light alarm signal immediately. Wide Detecting Frequency & Measurement Range: 20Hz~300Hz magnetic field and 20Hz~3500MHz electric field of working frequency range; 0.01~199.9μT(0.1~1999mG) magnetic field and 0~1999V/m electric Field of measuring range. User-friendly Design: soft operating buttons for the alarm value setting, MAX/AVG value switching, and units conversion, the mini pocket size EMF tester just powered by 3pcs AAA batteries, which makes it convenient for using and carrying. High Precision & Sensitivity: reliable for measure electric and magnetic field of mobile phone, hair dryer, computer, TV, printer, attendance machine, refrigerator, etc. Specifications: Material: ABS Magnetic Field Strength Range: 0.01~199.9μT(0.1~1999mG) Electric Field Strength Range: 0~1999V/m Magnetic Field Strength Resolution: 0.01μT/0.01mG Electric Field Strength Resolution: 1V/m Magnetic Field Strength Frequency Range: 20Hz~300Hz Electric Field Strength Frequency Range: 20Hz~3500MHz Temperature Measurement Range: -10~50℃ Temperature Resolution: 0.1℃ Power Supply: 3 * 1.5V AAA battery (NOT included) Item Size: 130 * 50 * 27mm / 5.12 * 1.97 * 1.06in Item Weight: 85g / 2.99oz Package Weight: 127g / 4.48oz Package Size: 19.3 * 7.5 * 3.5cm / 7.60 * 2.95 * 1.38in Packing List: 1 * EMF Tester 1 * Manual (English)