SmokTech TFV4 is one of the best tank systems in history and we are proud to offer this all-new design right now. It features two new patented sub-ohm coils: Quadruple Coil Head and Triple Coil Head, and two types of RBA head (single / dual coil), which will bring you a true premium experience. The top refill design makes filling as easy as it gets. The TFV4 also has an innovative drip tip and improved airflow system. All these are designed to provide you the unbeatable taste and quality.