A fixed 2.8 aperture, 180 degrees fisheye seems interesting. It will not be cheap though, I would expect it to cost more than a good used Nikon/Canon DSLR-era one, without autofocus.
However, this will be a fixed F2.8 lens.

Lens mount: E/Z/L/RF
PL versions available
Compatible Sensors: Fullsize
Focal length: 8-15mm
Lens construction: 13 elements in 9 groups
Maximum aperture: F2.8
Minimum aperture: F22
Aperture blades: 9
Minimum focusing distance: 0.16m
Maximum magnification: 0.23 times
Filter Diameter: –
Coating: Unclear
Size: 94.5×76.4mm
Weight: 650g
I am not sure what II is supposed to mean, but I do know Laowa designed something similar back then that was never turned into a real product. Perhaps this is the second iteration.
16cm minimum focusing distance is awesome, I would love to try this on my Z30/Z8.