Goldsource STU-300 Step Up/Down Voltage Transformer Converter - AC 110/220 V - 300 Watt Step Up/Down transformer converts 220-240 volts down to 110-120 Volts or 110-120 volts up to 220-240 volts. Simultaneous 3-mode Output: 5V (USB) / 120V (Standard US outlet) / 220V (Universal outlet) Four input voltages selectable: 110V/120V/220V/240V All range fuse protection with two spare fuses included. CE certified & 3-year manufacturers limited warranty