ELECTRICITY USAGE MONITOR: Monitor which appliance is the killer of the high cost of energy, help you save energy and your money BLUE BACKLIT LCD DISPLAY: The digital large backlit LCD display screen make it easy to read and record the data, especially in the darkness OVERLOAD PROTECTION: When the whole power exceeds the rated power of monitor, LCD will display "OVERLOAD" with booming noise to warn the user TIP & WARRANTY: It can store the last data so you can read the data after the power meter is pulled out from the socket. We take full responsibility for product quality. If you're not satisfied with it or any reasons, we will REFUND you in time. Order without worries This product is suitable for electrical equipment with power less than 3000W Working current: 13A Display power (W): 0W-3000W Current display (A): 0.0A-13.0A Time display range: 0-9999 days Frequency display: 0HZ-9999HZ Price display range: 0.00-99.99/KWH KWh and total cost display: 0.00KWH-9999KWH, 0.00-9999 Features: Recording frequency Record current Record power factor, power Record minimum and maximum power Record cumulative kWh Record time Record electricity costs Blue background light, read more clearly Abnormal display or no response with reset button Built-in 3.6V rechargeable battery (NI-MH), can store the total power and storage settings .