Uwell, the company was founded on the beliefs of providing only top quality subtanks. They only use high quality materials. With the dedicated research and development team, they always strive to bring new innovations and ideas into a reality in order to further advance the technology available in the vaping community. You can count on us to be innovators, always in search of new ideas to revolutionize the way people vape. They choose not to follow in the steps of the competitors vape stores. Uwell Crown 4 Tank is the upgraded version of Crown 3 which is still hot-sale in the vape market. With 28mm diameter featurs a very exquisite design, which holds up 6ml e-juice capacity and 5ml straight glass for you option.The biggest highlight of the Crown 4 is the advanced patented self-cleaning technology, the Uwell Crown 4 can absorb the e-juice in the condensation holder through regular usage and vaporize it. Moreover, Crown 4 Sub Ohm Tank utilizes UN1 Coil with 0.25ohm rated at 55W to 65W, and the UN2 Coil 0.23ohm with an output range 60W to 70W. The double helix coil design heats evenly and fully that gives the good flavors. Besides, the package included Dual SS904L Coil with 0.2ohm and 0.4 ohm offer better flavor and longer life with higher quality. 6 colors are optional. Technical Data: Size: 28*54.8mm Material: Stainless Steel, Glass & Silicone Coil type: Dual SS904L Coil 0.2ohm (70-80W) Dual SS904L Coil 0.4ohm (60-70W) SS304 UN1 Coil 0.25ohm (55-65W) FeCrAl UN2 Coil 0.23ohm (60-70W) Capacity: 6 ml(Bulb) + 5ml TPD Version Capacity: 2ml + 2ml UWELL Valyrian Sub Ohm Tank is a 25mm diameter sub ohm tank atomizer with 5ml capacity. It can be expanded to 8ml capacity by extra glass tube (not included). It features convenient top fill design with flip-to-fill mechanism and bottom adjustable airflow. The 0.15ohm resistance head comes with quad coils and parallel legs for better flavor. The tank comes with two drip tips with two sets of o-rings for matching. Technical Data: Diameter: 25mm Height: 62.3mm Tank Capacity: 5ml(8ml glass tube should be purchased separately) Material: Stainless steel/copper with pyrex glass Compatible Pin: Spiral type pin 95-105W, wave type pin 100-120W, unrestricted type pin 100-200W Color: SS, Black, Iridescent, Violet, Blue