The Subtank Mini retains the hybrid status of its bigger brother, allowing the you to opt for 0.5ohm stock Subtank OCC coils, or switch to the RBA base and build your own coils. The Mini has a diameter of 22mm and a 4.5ml liquid capacity.Features:1. Come with 2 modes: OCC mode & RBA mode 2. Use the newly patented designed Organic Cotton Coil (OCC), which tastes better than other materials 3. Support sub-ohm coils 4. Newly designed airflow control syste 5. Comes with a Pyrex glass tank with a huge capacity 6. Brass contact pin 7. 510 connectionNote:Users need to choose a suitable battery to match the OCC Sub Ohm coil. The battery output wattage for 0.5ohm OCC should be between 15-30W; for 1.2ohm OCC should be between 12-25W.OCC units are not compatible with other KangerTech clearomizers.