Bang and Olufsen Penta speakers question

Hello - I recently purchased a house that came with 2 Bang and Olufsen Penta speakers.  I can't figure out if they are Penta 1, 2 , or 3.  I'm not an audiophile per se, though I enjoy great music.  The speaker system we have now is wireless so it's time to offload the B & O speakers.  Any advice on how I can figure out how to identify the speakers I have, what distinguishes model 1 from 2 from 3?  I"d like to list them for sale on line and need that info and a ballpark asking price -they speakers are in excellent working condition.  Anybody interested?  thanks for reading, jamie