Tested with Fractal Design Define 7 / 7 XL cases, and can work with other Fractal Define cases. Tested with “Riser 009” PCB from Aliexpress, but can likely work with other Riser versions with the same mounting holes (they seems to differ mainly in power connections).
You can ether use it to install power-only cards (like SAS expander on the photo - no USB/PCI-E connection), or use as PCI-E 1x / 4x riser. These risers with this mount allows to brake out 1x/4x or M.2 slot into separate full size PCI-E (with reduced bandwidth - but it is often acceptable).
Print in PETG or ABS/ASA as elevated temperatures are expected (i.e. PLA won't survive).
The author marked this model as their own original creation.