As [answers to other questions][1] have explained, Bane wears a mask to provide pain management.  The problem with this is quite simple:

[![enter image description here][2]][2]
[![enter image description here][3]][3]

***The mask isn't attached to anything.*** 

One would expect a tank of anesthetic gas or something connected by a hose, but there is no such reservoir, and no hoses leading anywhere except within the mask itself.

##How can a self contained mask with no external sources of anesthetic substances do anything to mitigate chronic pain?  How does the mask work?


  [1]: http://scifi.stackexchange.com/q/20801/44025
  [2]: https://i.sstatic.net/eofmF.jpg
  [3]: https://i.sstatic.net/TXd9s.jpg