I changed my coil in BB today as per suggestions of closing airflow, dry pull, etc..it was super clean and before even putting it on the mod or sitting it down..I stood there and stared at it. Little beads of juice started to show up on the silver band above the airflow so I am guessing bottom o- ring. OF COURSE the only thing that didn't come in the box. I put the little vape band right around the bottom between the glass and bottom to kinda band aid the problem until I can get to vape store. Inspection of the oring, it appears flawless but I don't know what else could make it leak there? I watched a few of those videos and vacuum comes up a lot.