This is a taller version of the foot from the Jonsbo D31/D41 series of ATX computer cases. The purpose is to increase the gap under the case and improve airflow into the lower intake fans. The gap with the tall feet is now approximately 3cm which is about double that of the original feet.
There is a sacrificial single 0.2mm layer bridge in the counterbored hole so that supports aren't necessary. The screw easily punches through when attaching the foot to the case.
The example was printed in Prusa Galaxy Silver PLA with a 0.4mm nozzle and the 0.2mm Structural profile.
The author marked this model as their own original creation.