Yes they are.
SanTan Solar specializes in new, used and refurbished solar panels.
They actually have quite a few warehouses in Arizona and Georgia.
They get their solar panels from a variety of places, but all are above board, and thoroughly inspected.
If you do end up with a solar panel that doesn’t work as expected, they also do a great job honoring warranties (assuming the panel is within the warranty window).
I’ve had nothing but positive experiences with SanTan Solar.