Pre-owned and in Excellent Used Condition. These are great headphones. I recently tried a different pair (same model) on a four hour plane flight and the noise cancelling feature is awesome. 

When I started testing this set the voice prompt at turn on said 60% charge. The headphones were then tested for ~45 minutes and the charge was still announced as 60% charge after an off/on cycle. So, there is very good battery life left in these headphones.

The "R" & "L" covers on the inside of the cup have light staining (see pictures). 

All the buttons were tested and worked properly for the following items: 
  • Volume Up & Down 
  • Center Multi-function button for play/pause audio, answer/end call, double-press for skip forward, triple-press to skip backward to the previous track
  • Power/Bluetooth switch (slide switch) to power the headphones on or off (a voice prompt will announce the battery level) & to enter Bluetooth pairing mode (slide forward and hold). 
  • Left Earcup Control / Action button for switching between Quiet Mode (full noise cancellation) and Aware Mode (allows ambient sound in).
  • Microphone tested and working.
 Bose has an app to tap into some additional functions, but this was not trialed.