If your appliance is not dual-voltage, youll need a converter to step-down the 220-240 volt current in the country you are visiting to the 110-120 volt us current. If you fail to use a converter, and plug directly into a 220v250v outlet, your appliance will spark like the 4th of july and may even black-out your hotel. As a result, youll most likely be introduced to the universal definition of "not good". If you're traveling with certain devices, such as hair dryers and kettle, you may also need a travel voltage converter. The world runs on two types of electricity: 110125v or 220240v. North american devices run on 110125v electricity while the majority of the world runs on 220240v. Converters and transformers change the voltage of electricity to match the voltage of your device. Travel voltage converters are not designed for continuous use as oppose to the larger transformer which can be used continuously. Travel voltage converters also have very small capacity and usually range from 30w to 200w max. The 1600w or 1875w travel voltage converter is not an actual voltage transformer, it is designed specifically for heat producing (purely resistive) items only such a hair dryer, irons, heating pads, etc. Do not use 1600w or 1875w setting of a travel voltage converter with electronic items or any items with electronic circuitry or chipset.