Feature: 1. Digital LCD: This power metering socket has large clear digital LCD display for easy reading and it requires two 180mAh button batteries, which is shipped without batteries. 2. For Energy Consumption: The power metering socket is the killer of high cost energy appliances, helping you reduce energy consumption and save money. 3. Multi Functions:The energy monitor socket has overload alarm, power alarm, cost alarm, LED indicator and other alarm functions. 4. Overload Protection: When the whole power exceeds the rated power of the display, the LCD will display "Overload", accompanied by a rumbling noise to remind the user. 5. Various Parameters: Power, energy, voltage, amperes, power factor, cost, minimum and maximum power, which are ideal for energy consumption monitoring. Specification: Item Type: Watt Meter Material: ABS Gross Weight: 196g/6.9oz Product Size: 6.6x13.6x6cm/2.6x5.4x2.4in Plug: US plug Working Voltage: 120V ac Frequency Display: 50Hz Wide Voltage Range: 120V Working Current: Max. 15A Current Range: 0.005A-15A Power Supply Range: 1W-1800W Battery: 2PCS Button battery, L1154F 180mAh, capacity of one, delivered without battery. Package List: 1 x Watt Meter1 x Manual