I was wondering how the XL E2 V4 for 510 is? seems others have had issues but for a cartomzr with no filler/all ceramic that holds 2ml .......... doesn't seem to be a reason to make/buy a wetbox mod anymore since the little bottle used doesn't hold much more ....... I've seen them advertised $13-$18/5pk or $98/100 from manf. in China