FYI since this uses two 18650, they should be a matched pair, you should not use whatever 18650 you have been using singularly in other vapes, with another single 18650, at least that is true with other similar style vapes that use dual batteries.. much better for the cells to keep them as a matched pair always (as far as I know)
Edit: does that WPA have threading all inside it?? Seems like a needless reclaim trap if so for unnecessary extra cleaning although I guess it would keep your water piece cleaner??? Also could get annoying to have to have the 10 and 14 connection there if you are not using them, but I get why they would go with a metal multi adapter for the WPA and great that it is included...