Features: Made of flame retardant material, it is safe and durable to use. The large-screen can display voltage/ current/ power consumption/ power/power factor/frequency at the same time. Can measure voltage range of AC 110V-250V and maximal current of 100A. Equipped with current transformer, do not need to buy it separately. The blue backlight can be turned on/off manually. With overload alarm function, reset energy function, power alarm threshold preset function, etc. The data of accumulated electric quantity can be reset to 0. The product can lift a alarm when the current power is less than the overload power. Specification: Item type: Power Monitor Voltmeter Ammeter Maximum power: 22000W Maximum current: 100A Operating voltage: 110-250V Voltage accuracy: ±1% Current accuracy: ±2% Power accuracy: ±2% Execution standard: JB/T9282-1999 Function: measure voltage/ current/ power consumption/ power/power factor/frequency Application range: all home electric appliances with voltage of 110V-250V Product size: 85mm*47mm*28mm/3.35*1.85*1.1" Keys Operation: 1. Short press the button to turn on / off the backlight. 2. Long press for 3s to enter the overload power setting. 2.1 Enter the overload power settings, the factory default value is 4.4KW 2.2 The highest position flickers, short press button corresponds to the value plus 1, and long press for 2s is the shift, the settable maximum value is 99.9KW. 2.3 Without any keystrokes, it will exit after 5s and save data. 3. Long press 5s, system reset, accumulative power is cleared, overload power setting resets to default value. Attention: 1. The applied resistive load should not exceed the rated power of the product, or the product may be damaged, and cause a fire in severe cases. 2. The product is NOT waterproof, for indoor dry environment use only. And keep it away from spreading water when use in places like bathroom and kitchen. 3. Keep it out of the reach of children and away from fire. Do NOT insert foreign matter(except wires)into wiring holes. Please tighten the screws. 4. Do NOT unauthorizedly disassemble the product. Please get professional maintenance technicians or electricians when repairs are required. Note: Please allow 1-3cm (0.4-1.18") difference due to manual measurement and slight color variation for different display setting. Thank you for your understanding, nice day! Package Includes: 1 x Power Voltmeter Ammeter 1 x Current Transformer