When it comes to compact design and but big functionality, this is as good as it gets. The eGo-C Twist has a dial located at the base of the battery. This dial allows you to set the voltage output of the battery from3.2V~4.8Vin increments of 0.2V. Simply turn the dial to your desired vaping voltage. It features an easy to read numbered dial. *Please Note: Results may vary. Using the battery at a higher voltage output will drain the battery quicker than when using it at a lower voltage. Standard Joye eGo series batteries output a regulated voltage of approximately 3.7v.