Dual test functions: the EMF meter can accurately detect and measure the electric field radiation and magnetic field emissions at the same time. It can also measure the ambient temperature (/). Acoustic and visual dual alarm: When the value tested exceeds the preset alarm value, an audible and light alarm will immediately be generated. Wide detection frequency and measurement range: 20Hz ~ 300Hz magnetic field and 20Hz ~ 3500MHz electric field of working frequency range; 0.01~199.9T (0.1~1999mG) magnetic field and 0~1999V/m electric field of measuring range. USER-FRIENDLY DESIGN: Soft control buttons for alarm value setting, MAX/AVG value switching and unit conversion, the pocket-sized mini EMF tester only powered by 3 AAA batteries, which makes it easier to use and carry. High precision and sensitivity: reliable for measuring the electric and magnetic field radiation of mobile phones, hair dryers, computers, TVs, printers, presence machines, refrigerators, etc. Features: Acoustic and visual dual alarm: when the tested value exceeds the preset alarm value, an audible and light alarm will be generated immediately. Wide detection frequency and measuring range: 20 Hz ~ 300 Hz magnetic field and 20 Hz ~ 3500 MHz electric field of the working frequency range; 0.01~199.9T (0.1~1999mG) magnetic field and 0~1999V/m electric field of measuring range. User-friendly design: soft control buttons for alarm value setting, MAX/AGG value switching and unit conversion, the pocket-sized mini EMF tester that only powered by 3 AAA batteries, making it easier to use and carry. High precision and sensitivity: reliable for measuring the electrical and magnetic field radiation of mobile phones, hair dryers, computers, televisions, printers, attendance vending machines, refrigerators etc. Specifications: Material: ABS Magnetic field strength range: 0.01~199.9T (0.1~1999mG) Electrical field strength range: 0~1999V/m Resolution of magnetic field strength: 0.01T/0.01mG Electrical field power resolution: 1V/m Frequency range of magnetic field strength: 20Hz~300Hz Frequency range of electrical field strength: 20Hz~3500MHz Temperature measuring range: -10 ~ 50C. Temperature resolution: 0.1 Power supply: 3 x 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 x 7.5 x 3.5 cm / 7.60 x 2.95 x 1.38 inches Box contents: 1 x EMF tester. 1 x user manual (English)