Thanks for the replies. There are no markings that I can see, however there are two threaded holes on the back for mounting. I will try and take a picture with lower resolution to see if that reduces the file. I travel a lot so I may not get it done for a bit. By the I fly to Texas tomorrow
but I bought them from a guy that advertised them in the San Jose Mercury and met him just outside Los Gatos in the Santa Cruz Mountains.