The Subtank is a brand new revolutionary tank from KangerTech.The Subtank provides you with the option of using this unit as an RBA or with and the new OCC (Organic Cotton Coil) coils, KangerTech's newest innovation. The Organic Cotton Coils are made with Japanese Cotton, have a unique square shape and are said to have a longer life span, and a larger heating section.This feature packed device comes fully equipped with a new adjustable airflow control, a sturdy tank and a spring loaded 510 connection. The Subtank gives you the choice of using the pre-installed OCC coils or the new RBA coil head if you prefer building your own coils. If you want to enhance your vaping experience, the Subtank is perfect for you.Dimensions: 2-1/4"L x 1"D(without tip)Spring-loaded 510 connectorBase hardware: stainless steelNew adjustable airflow control for superior airflowNew Organic Cotton Coil HeadOrganic Cotton made in JapanChoose between RBA or OCCOCC holds 6 mL of liquidRBA holds 4.2 mL of liquid510 tip compatibleWarning: This tank uses a sub-ohm resistance. It will only work on a mechanical mod or a mod capable of 30 watt or higher. You must be sure that your mod AND batteries can handle SUB OHM coils. If you're using an electronic mod, make sure it can handle the amps. For mechanical mod users, please use 30 Amp batteries or higher.