A while ago I bought a Russian 91% clone from fasttech. Worked well with my mvp and nemesis clone and I was a happy camper up until I bought a 4nine. I kept shorting out the batteries being that the 510 pin inside the russian was recessed into the kayfun. I bought a hammer and couldn't use it with the russian because it wouldn't make contact with that damn pin. As you know you really can't loosen up that pin cause it will also loosen up the interior base where you put your coil on. After endless research I came across fatdaddyvapes.com and found a center post with adjustable pin. While it says it's for an authentic russian, to my delight it also fit the fasstech russian clone! Buyaaa. I'm a happy vaper again! Here's a pic of what you need! 
