Here's the whole story, please read! This is the second Kayfun Prime clone that I've had this problem with. When I couldn't get my original one unplugged, I bought two new ones from Fasttech. When they arrived, one wouldn't pass any air. I believe something wasn't drilled through or wasn't machined correctly. The other one had one of the coil attachment screws stripped. I managed to scrounge parts from one of the new ones to get my original one working. Until now, when it also plugged up. So I went looking for parts again. The part I needed, the only one left, had the stripped screw. The screw was all the way in and trying to unscrew it, it just turned round and round but didn't come out. So I got a knife blade under it and forced it up while turning it with a screwdriver. I didn't know whether the threads in the coil base would be good or not. But it turned out they were. So I scrounged a screw from the other clone and made a new one from parts. It's working well. These things are a bitch to attach the coils to. I've seen some attys that have a hole to poke the wire through and a screw to hold it there. That would be easier but I don't remember which one(s) had that. Fortunately I almost never have to change a coil. Anyway, I want to mention some changes to the design from my original one. If I remember correctly, my original came with two tanks; one solid stainless steel and one glass. I think I must have broken the glass one; can't remember when I last had it. The new ones come with a stainless tank that has a narrow band of semi-transparent material at the bottom so you can see when your juice is getting low. The new tanks fit the old attys. Apparently the quality has gone down as both new ones had serious issues and were unusable as shipped. I used them for parts, twice. So I have a working one again. But I am a very heavy vaper, so I'm sure I'll need a new atty in the future, and I don't trust the new ones to be functional. If anyone knows a good rebuildable tank atty for not too much money, please let me know. Thanks for reading.