Compact and comvenient, easy to use. This product will make your life easier and convenient. Features: 1. Electrical parameter measurement function (voltage, current, active power, energy, frequency, power factor) 2. Overload alarm function (over power alarm threshold, backlight and power flashing to alarm) 3. Power alarm threshold preset function (can set power alarm threshold) 4. The energy can be reset use the key 5. Store data when power off 6. Large-screen LCD 7. Backlight function 8. Key Function Backlight control Short press the key to turn on or off the backlight, the backlight has memory function, it can store the on or off state when power off. Reset energy Step1: Long press the key for 5 seconds until the energy value flash, then release the key. Step2: Short press the key again, then the energy value is cleared and exit the reset flashing state. Step3: If there is no operation on the key within 5 seconds, it means the energy value is not cleared and will exit the reset state. Set power alarm threshold Step1: Long press the key until the LCD screen display SET CLr, then release the key to enter the setting state Step2: Power window display the current power alarm value and the last digit begin to flash, then you can short press to plus 1, when there is no operating over 3 seconds, it will switch the digit position automatically, the setting method is as same as the above. Step3: After finish the setting, long press the key over 5 seconds will store automatically and exit, the range of active power threshold is 0.0~2.5kW. it can display six parameters at the same time. Specifications: Working voltage: 80 ~ 260VAC Test voltage: 80 ~ 260VAC Rated power: 100A/22000W Operating frequency: 45-65Hz Measurement accuracy: 1.0 grade Size: 9*5*2.5cm Wire length:19cm Weight: Approx.110g Display format: 1.Power Test range: 0~22000W Starting measure power: 0.2W