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Goldsource STU 300/500/750 Watt Step Up Down 110V 220V Voltage Converter Transformer

All of our mats run on the US electrical standard of 110v. In other counties, you may purchase a power converter with a wattage that’s appropriate for the mat. We offer converters on our website as well, but these are powerful, professional units that are expensive to ship due to their weight (3-6 kg.).

Created by one of the best manufacturers in the industry, the Goldsource STU series step up/down voltage transformers offer you a secure, stable, affordable & convenient solution to converting voltages from 110-120 volts up to 220-240 volts or from 220-240 volts down to 110-120 volts for both home use & industrial applications.

The STU-300/500/750 is determined at 300/500/750 watts maximum correspondingly. It highlights a heavy-duty cord with a standard US 3-prong plug plus a free American to German outlet plug adapter. There is a sum of three outputs on the front panel. Two are grounded outputs, one designated for 110 volts with a US standard outlet, the other for 220 volts only with a universal outlet. The last one is a 5V standard USB jack, a unique feature of the STU series & 1st in the industry. And most importantly, all three outputs can be used simultaneously & continuously.

For security, it’s endorsed by the manufacturer that the voltage transformer’s highest power should be equal or greater than the power rating of your appliance multiplied by 1.5. For example, if you have an appliance rated at 100 watts, you will need to pick a transformer with a maximum power of 150 watts or higher.

*This converter cannot be purchased on its own it has to be purchased with a healing mat. No additional charge for shipping in within United States. Please inquire for shipping quote if you are an international shopper. 


  • Input voltage: 110/120/220/240 V/AC selectable
  • Output voltage: 110/220 V/AC, 5V/DC USB
  • Dimension: 7 X 7 X 5 inches
  • Weight: 4 lbs 12 Oz
  • Power cord length: 3 ft


  • 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 & 2-year manufacturer’s limited warranty.

What’s in the box:

  • Goldsource STU300/500/750 voltage transformer
  • Spare fuse: 2
  • Universal plug adapter

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