Volts are supplied to the atty/carto from the battery. Most devices, such as the EGO supply approximately 3.7V. High voltage devices can supply between 5-6 volts. Variable Voltage devices allow you to adjust the output voltage. This varies between devices, but usually somewhere between 3V up to 6V. Multi-voltage devices provide pre-determined voltage setting. For example, a low setting could be 3.7V, a medium setting could be 4.5V, a high setting could be 6V.VTF: Abbreviation for Vapor, Throat Hit, Flavor.