hi.
been vaping now for 2yrs always used the 901 with virgina 36mg so think it is time foe a change, going to get the 510 titan,
now i have lots of 901 refillerble carts can i use them for the titan or do i need a adapter.
No, there isn't one anyway. Some will fit, some will not, I personally use Titan carts on my 901, and have done so vice-versa, too. It's a case of suck it n see. 901's on Titans are going to always be exceptionally tight fitting, the reverse is not always true though