The Ego-C Twist kit includes a battery, 1 Aspire Vivi Nova-S BDC and 1 USB cable and wall adapter charger. The Ego-C Twist has a variable voltage rating of 3.2v - 4.8v and be changed by twisting the bottom cap. Each battery contains a safety feature which turns on/off by clicking the button 5 times and the LED button will blink when successfully switched into these modes. If a short is detected, the battery will shut off automatically until the short is removed. It is compatible with Ego threading and any 510 related fitments such as the Aspire Vivi Nova-S BDC that is supplied in the package. All that is needed to start vaping is liquid.