The VapePen 510 Thread Twist Variable Voltage Vaporizer Battery is a new level of convenience! The Twist is a variable voltage battery allowing you to choose your preferred voltage between 2V-4V by dialing the rotary switch located at the base of the battery. The Twist is available in a number of different colors to ensure that it will look great with any attachments you have, as well as match your personality. Included is a USB charger for convenient charging of your battery, simply plug it into any USB slot or USB enabled wall charger. With the Twist battery, you have full control and maximum power for the ideal vaping session every time!