Why does one need a frequency converter? Devices with motors that turn or vibrate are dependent on power line (mains) frequency to do their job properly and at the right speed. If one owns a device designed for 50 Hz (manufactured in Europe or Asia) and one wishes to power it in the USA, it will run about 20% faster without frequency conversion. The reverse is also true. With KCC/Amgis voltage and frequency converters, simply select the voltage and frequency needed from the front panel, and plug it in. It is also remotely programmable for production test.