Salutations everyone, It's still about devices offering "obvious" paths. At first i made an attempt with handhelds: FC: SEE-THRU battery-operated portables? (2014-Mar-10) This time i'm getting curious about pen vaporizers after i got 15 minutes alone with a Snoop Dogg: its electronics and battery DO NOT share any part of the fresh/air path (and much less the vapor one); although its vaporizer function felt quite perfectible (...) this is one herb vaporizer which people can use without having to worry about ventilating electronic hardware through herb. Additionally, everything in the bowl itself has been made visible so it's easy enough to gather what fresh-air is going through before it passes the heater. No misterious black-box concept here, so if the reader can think of similar cases which will compare in terms of path(s) containment vs potential contaminants, etc., then i'd like to be told about it... Very much.