The SMOK X CUBE II is a substantial upgrade in all aspects. As one of the most accurate temperature-control mods, X CUBE II features three new functions: Intelligent Coil Recognition, Adjustable Temperature Coefficient of Resistance and Adjustable Initial Resistance, which are designed to bring your vaping experience to the next level. It has 160W maximum output，Bluetooth 4.0 technology, and a customizable LED that potentially illuminates in up to 16 million colors. And there many more functions are waiting for you to discover. All these make X CUBE II one of the most excellent devices ever made. Requires two (2) 18650 battery cells (not included).