Measures various parameters: power (W), energy (kWh), volts, amps, hertz, power factor and maximum power (W), time, days - kWh is vital as this is what your electricity bills are based on! Large, clear LCD display for easy reading (screen dimension: 45mm x 70mm). Cumulative Kilowatt-Hour Monitor. * Calculates electricity expenses. Electricity price setting by pressing COST, FUNCTION, UP and DOWN button according to the instructions. * Sets electricity price value which ranges 00.00COST/KWH ~99.99COST/KWH. Displays volts, amps and wattage accurate to 3%. * Low power consumption. Built-in Battery(3.6V rechargeable batteries ) backup - allows meter to be moved (and viewed) without losing readings. * NOTE£ºIf an abnormal display appears or the buttons produce no response, the instrument must be reset. To do this, please press the RESET button.