First, some background: In the US and some other countries, the power supply from wall sockets is 110 volts (110V). In other countries, particularly Asia, the power supply is higher at 220 volts (220V). The chargers for common devices (phones, laptops, electric razors, etc.) that are generally carried by travelers internationally are made to work with both types of power supply. If you look at the power rating on the charger, you will notice that it is marked something like "110V - 240V". A charger that is not meant to work internationally will only be marked as 110V or 220V. If you plug a 110V device into a 220V socket, it WILL fry/smoke/burn unless it has built-in protection circuits. It's a fire hazard and the device will immediately become useless beyond repair. But vice versa if you plug a 220V device into a 110V socket, the device simply won't turn on. Some devices may still get damaged by the low voltage like motors, refrigerators, etc. if you leave them on too long but in most cases, nothing will happen. Now even if your device is dual voltage, you may not be able to use it because the shape of the pins on your plug may not match the holes in the wall socket. In such cases, you just have to get a simple plug adapter. Plug your device into the adapter and then plug the adapter into the wall socket. Plug adapters won't cost more than a few bucks. But if your device is not dual voltage, then you will have to buy a voltage converter/transformer that converts the voltage from the wall socket to the voltage required by your device. The type of transformer you should get depends on the wattage rating of your device. Look for a number followed by a 'W' next to the voltage rating, that will be the wattage. For example, 12W or 50W, etc. Make sure the wattage of the transformer you use is higher than that of your device. These transformers can be expensive and the cost depends on their wattage. Higher the wattage, higher the cost. They can also tend to get heavy for a higher wattage. I have a 250W transformer that weighs around 4 lbs (~2 kg). Now, the point of this thread: I bought my Zelda edition Wii U in the US last year and brought it back home. The power adapters for both the console and the gamepad clearly state that they are 110V only. But this is a lie. I came across this blog post on IGN where someone opened up their US adapters and discovered they were actually dual voltage! They plugged their supposedly 110V only adapters directly into 220V sockets and they worked flawlessly. I tried it myself and I confirm the 110V adapters work well with 220V sockets. I just needed a simple plug converter to make the pins fit into the wall socket. I wish I had found this out sooner before spending $20 on a transformer. I'm not sure if the reverse case (220V european adapters with 110V wall sockets) will also work but it should. Using a multimeter I checked the output of the adapters with both input voltages and it remained the same. I hope this helps people that want to import Wii U consoles from other regions. There is no need to buy transformers or new adapters for their region. DISCLAIMER: If you want to try this out, do it at your own risk. I took the risk and it worked for me. I will not be responsible if something goes wrong and you end up damaging your adapters/console. Doing this WILL void your warranty but I doubt Nintendo will ever find out. Remember, this works for the Wii U ONLY. It most probably will not work for other Nintendo products like the Wii, 3DS, etc.