I fix batteries for Central Iowa E-Cigs in Des Moines,Iowa. The majority of this work is simple re-soldering loose wires ,replacing missing buttons/stuck buttons, and installing new rubber gaskets in the head around the positive fire-pin in egos mostly. I took a king and queen model passthrough and removed the mini charge port so I could solder wires in and install in its place, another head. A Dual headed ego to accept a tank at each end. Here's the video at...Video 31 - YouTube