If yours is like mine, it is completely unbranded. You have no idea who
or what made it. I did find out that it is a unit made in China, sold under
several different brands. I had some success finding a manual by
following the lead in this link:
NESA Vision NAV-6510 (nav6510) In-dash Double DIN 6.5" TFT-LCD
I even sent Nesa my flash drive and they updated the maps for
me without charge, but I did not tell them it was the unbranded
cheapo that Mobile Optics, who is a re-seller, supplied
to Thor/Damon for a while, but they stopped since the unit has
a lot of performance issues.