The Kanger variable voltage battery is a stylish, flush button, high capacity battery that allows for the voltage to be changed on the fly by rotating the dial at the base of the battery. This allows for the voltage to be changed from 3.3v up to 4.8v with clear markings at 3.3v, 3.8v, 4.3v and 4.8v. If you already have an eGo style device and are looking for longer battery life as well as the ability to increase or decrease throat hit/vapour production then these batteries are for you.