This is a mount designed for optical drives to be mounted on the underside of a desk.
Having upgraded my case to one without 5.25" drive bays I needed to place my drive outside the case.

Planning to make myself a new desk anyway I decides to include an actual mount for the drive.

I used the official SFF specs and drawings for the 5.25" ODD form factor to design this mount.

USE V3 - V1 and V2 fit badly, probably due to material shrinkage

Version 2 - Side Holes Added

Version 3 - Width increased slightly for better fit, Bottom grid holes removed

Creality

Ender 3 Pro