Pro Tank II is a bottom coil Clearomizer glass tank system with replaceable atomizer heads and has a eLiquid capacity of about 2.5ml. Replacement atomizer heads for the Pro Tank II Clearomiser replaces the burned out element of your Pro Tank II with this product to get your clearomiser up and running again. Saves money on buying a new Clearomiser. Newer Bottom Burn Coil (BBC) Design to reduce coil burn. On average will last the user 14-20 days before the coils/atomizer heads will need to be replaced, however, this is dependent on the users vaping style. Available in 7 Colours.