Charger console recorder and mic - common or rare? - Craigslist ad

[Dans 68]

While perusing CL I happened upon this ad http://sfbay.craigslist.org/sby/pts/1595853137.html regarding a Charger console recorder and mic. I have seen this item in literature before, but cannot remember where or the era. Was this a '70 and later item? I'm guessing this is somewhat rare as I have not come across them before. Anyone have any history with this item? 

Dan

[Ghoste]

For B-bodies I believe 71 was the first year offered.  Not exactly rare but not all that common either.  Remember, the 8 track was still king at the time.