Those little kanger tanks that used the naturevape coils are the only ones I had that used 510 airflow.
.. but all the popular mods had it for years after, the coolfire, eleaf, wismec etc.
I think the demand from vapers was clean looking, flat, flush 510's though.
There were all different designs
@LordOdin
This is a wismec presa the airflow is actually designed into the top of the mod .... it's a little hard to see because it's old and black but it has a gap at the front edge, then like a channel all around underneath, then 2 slots front and back where the screw part is.
White arrows are slots, blue arrows is a circular channel same height as the slots and the red arrows are flush with the top of the mod. ... so even if you had a tank that overhang the air would still come in from that top slot.
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