The Exxus Tap VV 280 mAh 510 Touch Activated Battery by Exxus Vape is thoughtfully designed to be simple and unimposing. This fact about its appearance make it an ideal match for a variety of tanks. The voltage of this battery is adjustable, this fact is what makes it a variable voltage device. The output power can be changed from anywhere between 3.3V and 4.2V. With a 510 thread attachment component, to chnge the temperature you simple tap the front of the battery and it will change heat temps.