One bored..

[dave]

OK macca, let me know if it's of any use. It looks like a 510 - eGo adaptor but has no thread on the 510 end. The eGo battery or atomiser connectors I have seen look different, so I haven't got a clue what this is supposed to be for, unless it is just a manufacturing fault.

[maccafan]

I thought about it and the only answer I can come up with is the same as you. That they forgot to cut the threads.

I think 510's are 7 x 0.5 threads so if you have or know someone who has a tap & die set should be fairly easy to cut some threads.