I bought a sigelei Z-Max V5 and it came with a C4 atomizer that didn't work. Let the buyer know and they sent me another but it's not working either. I tried it on the sigelei and then tried it on my VTR with the same results. One doesn't appear to make contact and the other does when I screw it down tight. The problem is, neither will let air flow so I can draw from them. No air flow what so ever. I can unscrew it a bit and the air flows but then I loose the connection. The listing says it has 510 or ego threading but it appears only the Ego is on it because I can't get the base to unscrew or anything. Did the search thing here but can't seem to come up with anything similar. Any ideas?