This is a voltage regulator/stabilizer with built-in step up/down voltage transformer. Converts 110/120V to 220/240V or converts 220/240V to 110/120V (switch is on back of unit). Maximum capacity is 5000-Watt including the power surge. Compatible with 50Hz/60Hz. This stabilizer can regulate big range fluctuating voltage into general voltage output. Input Voltage AC 75V-130V or 180V-260V. Output Voltage: AC 110V+-4-percent or AC220V+-4-percent. On/off switch with indicator lamp. Analog meter on front of unit shows exact output voltage. Voltage stabilizer good for countries with unstable voltage supply. 5 Outlets on guide: Remember to leave at least a 100-percent slack for the voltage converter transformer. Televisions, heating appliances, laser printers and power tools spike when you turn them on. F