At first glance, both Kroma-A/Zenith & Coolfire Mini/Zenith are listed as containing 22mm tanks with 2ml capacity - based on the links above. But, going to a US site, I think I did see a 4ml capacity tank option.
Is the Plexus Z-coil head for sub-ohm only? Just curious.
I take it you all are suggesting this/these because they-re less likely to leak??