I have boxes from 3 different vendors, E2 510's ceramic. I threw away 60 standard 510 cartomizers after I used the first one of these.
I have had NO problem from them, and they vape great.
Again, we know what opinions are like, and mine didn;t have jacked up threads, but my first ones I got 2 weeks ago have lasted all that time with lots of refills in each one.
I ordered from 3 different vendors to get 3 different colors.