It is also worth mentioning that if you really need a converter (not just adapter) it is essential to check its specs as well. Typically devices that require specific voltage require also so much power that small converters cannot handle it. That's why converters are not usually of much value for travellers. Single voltage devices are usually ones that create heat like hair dryers. If you need one for travelling, it is better to buy dual voltage one or different device for travels in countries with different voltage.

But it is always best to check, because wrong voltage and therefore wrong current is a real fire hazard.