Brief Introduction of SMOK TFV4 SMOK released TFV4 in Jun 19, 2015, which features quadruple coil and RBA head, top refill design, improved airflow system and innovative drip tip to give fans unexpected vaping experience. 1. Drip tip system There is a one-or-two millimeters spacing between the outer and inner tube, which can be a heat shield to prevent the outer tube overheating, and keep your warm vapor dry simultaneously. 2. Four types of coil head Four types of coil head to meet your different vaping demands
3. Adjustable airflow system Four large air slots evenly spaced on the dip tip, which can allow you to have an extremely open draw.
4. Top refill system Top refill design makes filling as easy as it gets.
5. Parameter Dimension: 24.5mmx70mm Weight: 92g Material: Glass & Stainless Steel Capacity: 5 ml Thread: 510 Coil: three coils
More details refer to this link: http://www.smoktech.com/atomizer/tfv4.shtml