This is an Alternate half drive 5.25-inch drive cage for the Fractal Designs R5 Computer Case.
 

I updated my computer to some newer technology and wanted to add a water-cooled CPU cooler. The cooler I chose had a 360mm radiator.
The Fractal R5 had limited locations for a 360mm radiator. One location to use was at the top of the case.

My case also had an internal 5.25-inch Blu-Ray/DVD/CD recorder installed, and I didn't want to lose the use of it. The 5.25-inch drive cage interfered with the installation of the 360mm CPU cooler radiator.

Most new computer cases which I saw for sale, no longer include a location for using an internal Blu-Ray/DVD/CD drive. It seems everyone is moving away from these, or they are using external drives.
 

I took some time and designed a half size drive cage that would mount into the lower portion of the Fractal R5 location for mounting of the DVD recorder.

This worked perfectly!

You can see the size difference between the original drive cage, and the one I designed:

Now my case can fit both the 360mm CPU cooler radiator and still allow use of my internal 5.25inch Blu-Ray/DVD/CD recorder! Notice that the CPU Liquid Cooler Radiator above the drive cage, you can see the fan has enough clearance now.
 

I printed this in PET-G.