Rebuildable Drippers (RDA)
RDA's (rebuildable drippers) are similar to tanks, in the sense they have cotton and a coil, but these types of tanks do not hold chambers of e-liquid and should only be used by advanced vapers who understand coil and battery safety.
These types of tanks allow users to fully customise their vaping experience, creating the specific ohm resistance they want with the certain type of cotton they wish to use.