The use of broadband pass technology within device which means being more sensitive than other EMF meters in picking up electromagnetic frequency.There are 5 colour LED signals to different level of magnetic field. It is suitable to use either indoor or outdoor applications for measuring any electric device, power lineMeasure wide spectrum of EMF from 50 to 20,000 HertzIdentify potentially harmful long term overexposure to EMFSensitive in detecting electromagnetic field. Simple & user friendly device. Light weightSpecificationsDetection range: 0 to 20+ milliGauss (mG)Detection frequency: 50 / 60 Hertz (50 to 1,000 Hz - ELF; 1,000 to 20,000 Hz - VLF)Accuracy: +/-5% (Typical)5 LED signals for different level of magnetic field:Green (1) - Normal magnetic field (0 - 1.5 mG)Green (2) - Low level magnetic field (1.5 - 2.5 mG)Yellow - Mid level magnetic field (2.5 - 10 mG)Orange - High level magnetic field (10 - 20 mG)Red - Extreme high level magnetic field ( 20mG)Operating temperature: -18 to 49Celsius (0 to 120Fahrenheit)Power source: 9V batteryWeight: 170gcolour: blackMaterial: ABS, Electronic componentsize: 14.6*5.8*25.5cmPackage Contents:1* K-II Electromagnetic Flowmeter1* Instruction ManualOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.