The Uwell Crown IV tank is a beautifully crafted hand polished design that’s made of combination of stainless steel and Pyrex glass, that has top fill design and bottom adjustable airflow. With advanced patented self-cleaning technology, the new Crown 4 tank can absorb the e-juice in the condensation holder through regular usage and vaporize it. The Crown 4 tank utilizes Dual SS904L coil and Double helix mesh coil to achieve heating evenly and produce excellent flavour.