Here is a link to the server rack this was designed for https://www.snapav.com/shop/en/snapav/sr-fs-system-dc-21u

This was designed to be able to store a synology NAS on top of the rack unit and run all the cable through the punch out without risking damage to the cables. Can be used to run just about any cables to any equipment on top, like an xbox, or something that runs too hot for the inside of the cabinet, or any wifi/Bluetooth devices, ect.

I have noticed that some slight scaling will need to be done as the knockouts on each rack will never be exactly the same.

It had to be designed in two parts in order to fit the build plate (X1C), but I used that opportunity to place the split where the NAS ethernet cables go though.