Features: Electrical parameter measurement function (voltage, current, active power, energy, frequency, power factor) Overload alarm function (over power alarm threshold, backlight and power flashing to alarm). Power alarm threshold preset function (can set power alarm threshold). The energy can be reset use the key. Store data when power off. Large-screen LCD Backlight function. Appearance and Key function Specification: Brand: PEACEFAIR Model: PZEM-018 Working voltage: 80 ~ 260VAC Test voltage: 80 ~ 260VAC Current: 5A Rated power: 5A/1100W Operating frequency: 45-65Hz Measurement accuracy: 1.0 grade Size: 9*5*2.5cm/3.5*2*1in Weight: Approx.85g/3oz Package list: 1 * Digital Meter Display Interface Display interface is large-screen LCD, it can display six parameters at the same time. II.Display format 1. Power: test range: 0~1100W, Starting measure power: 0.2W 10W display format:1.00~9.99W 100W display format:10.0~99.9W 1000W display format:100~999W 1000W display format:1.00~1.10kW 2. Energy: test range: 0~999kWh 1kWh display format:0~999Wh 10kWh display format:1.00~9.99kWh 10kWh display format: 10~999kWh 3. Voltage: test range: 80~260V Display format: 80~260V 4. Current: test range: 0~5A,Starting measure current: 0.001A Display format: 0.000~5.000A 5. Frequency: test range: 45~65Hz Display format: 45~65Hz 6. Power factor: test range: 0~1PF Display format: 0.00~1.00PF Key function 1. 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. 2. 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. 3. 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. Note: 1. This module is suitable for indoor, please do not use outdoor. 2. Applied load should not exceed the rated power. 3. Wiring order can't be wrong.