Ive been patiently waiting a few weeks for the clone dual coil rda to arrive and it finally came today. Ive been using a few different rbas with my vamo recently, a aga-s, vulcan, phoenix rda, and a mini cobra which have all threaded on perfectly in the past. I tried to attach the rda as i usually would to find the bottom connector flathead bolt on the rda stuck out a couple mm. This allowed me to get only a couple of threads at the way bottom of the 510 connector to catch on the vamo. then I filled the bolt until it no longer looked like a flat head bolt. This should have freed up a few more threads. I connect it to the vamo and it went on a bit smoother but still it seemed very loose compared to the other rbas while i was attaching it. I set it up, got it running with a new single coil and it worked ok, needs a little more air flow for my taste but thats an easy fix. I took it off to check it out again, and when i put it back on it wouldnt tighten on at all. I could literally insert the rdas 510 connecter all the way in with out tightening it and wobble it a little! I thought i stripped my vamo big time some how, but i am one to snug things up easily. I put my phoenix m3 rda on and it screws in just fine. then the aga-s, same thing. whew i thought i ruind it. then i try the mini did, and its a bit more wobbly now and catches far less threads but still tightens up. The nimbus clones threading isn't as round in diameter as the other ones i have. Its off by at least .5mm. Thats a lot for threads! Im going to get a tank flow connector now and one specifically for this clone so i don't ruin a bunch of connectors with it and that should help with prolonging the poor threads in the vamo.