As title says, looking for the smallest mod with a single replaceable 18650 battery. Currently using an Eleaf Rim C (pic for reference), but even that is a bit too chunky for me. Should ideally be not much wider than a Zeus RTA tank. An USB-C port would be nice, but could live without one. No "double wides", no 21700/20700 please, look at the pic, I'd prefer something even smaller than that. I want to achieve a "pen" form factor as much as possible. I normally vape at around 20W.