It's not just the fan, it's the solar
, so batteries (depending on model) and the mounting -- Since these are usually designed to fit on boat decks, it should have a system to prevent water leakage -- By the time one adds all that to the computer fan...
In fact, the heart of it may well be a computer fan!
Not intended to replace a fantastical fan, just to vent moisture and odors from bathrooms, small marine bunk rooms, etc. Even in shade, it's going to move some air.