LOL..... sorry, I just "discovered" the Infinity while looking for a more apropos VVPV for my wife. The one I currently use is too heavy and also too large for her hands. I read about the Infinity several times and man, am I glad I went to the Notcigs site and checked them out.
To date, my wife and I have only used 510
devices and I got to thinking that we were sort of "boxed in" in terms of options. Yeah, we could
buy adapters, but after reading some of the replies, it made more
sense to me to get the 901 conn vs the 510. Now, with a few adapters, we have many more options. Also there have been some problems as 5C pointed out with the center post on quite a few of the 510 atty's and carto's. Then, when BuzzKill chimed in with his very neutral opinion about 510 conn's, my mind was made up. I'm sure you have read BuzzKill's comments in this thread.
All is not lost for you though, fourboxers..... pick up some adapters and then you will have more flexibility -- you will just be going in the "opposite direction" when buying adapters going from the 510 to the 808 or 901 conn. I can't count how many times I wanted to pick up some 510 CE2's only to find all the 510's sold out, but plenty of 808's still in stock. Now, we have the flexibility to "swing several ways".
I do think that "extension and connector" you referenced is the right one -- I can't remember which thread that was in now. I was sort of waiting for confirmation to be sure, but after looking closely at them, I'm pretty comfortable that is the correct conn.
No matter which conn, I'm sure you are gonna love the Infinity. I'm anxiously awaiting the arrival of the one for my wife. Plus, when you decide you need a back up Infinity, you can order that one with the 901 conn!!!!
Whew, I type too much....... horton ----- out
PS.... use a paper clip or a dental pick to gently pull that center pin out. Just be gentle and don't try to move it too far. Doesn't take much movement to get good contact.