The next term in the rating is the intended Frequency for the device. Frequency is the number of times that the electric current switches polarity per second, expressed in a standard called Hertz, or abbreviated Hz. On electronics with motors that turn or vibrate, frequency will determine the speed at which they operate. Some devices will indicate 50/60Hz, which means it can operate at either 50Hz or 60Hz and perform well. However, many devices are designed for only 50Hz or only 60Hz, but not both. North America: 60Hz Rest of the World: 50Hz Again, some exceptions exist. Taiwan is 60Hz, as is Venezuela, Ecuador and Colombia. The western half of Japan is 50Hz and the eastern half is 60Hz. So it is always prudent to check!