Oh, thats just a simple 50mm radial fan (blower fan) I use on my 3D printer. I'm designing a bracket to fit onto the M.2 extender PCB so I can use it as a M.2 cooler.
Might look for an alternative fan for it as I noticed these ones make a ratling sound when not at 100% and are a little to noisy at 100%.
Looks more slick than the other method I’ve seen of sticking a tiny Noctua fan above the heat sink