Review on 2000W ST-Pro Auto Step Up & Step Down Voltage Transformer Converter with US Standard, Universal, Schuko AC Outlets & DC 5V USB Port by Goldsource - Heavy-Duty 110/220V Converter [3-Year Warranty] by Steve Cypert

This is an autotransformer. Because the transformer only has three leads, it does not provide isolation. If you use it to boost the voltage, the output will be 230 volts from neutral or ground. Twice as much as usual. I plan to use it with a generator to power my well pump during a power outage so insulation won't be an issue. I removed the cover to check the circuit and found a mis-soldered wire on one of the outlets. It was 12 ga wire held by just a few strands. I had no intention of using this socket, but it could break and create a dangerous situation. To update. After several hours of testing, the fuse holder failed. Poor contact with the fuse and holder resulted in an unpleasant odor in the electronics. I had to replace the fuse holder. Poor quality, unreliable device.