Case for Raspberry Pi 4B can be found under the name iUniker Case.
https://www.amazon.com/iuniker-Raspberry-Heatsink-Without-W-Shape/dp/B07ZVKN262/ref=sr_1_5?crid=1R6GJFAR9K273&keywords=iUniker+Raspberry&qid=1695058702&sprefix=iuniker+raspberry%2Caps%2C156&sr=8-5
It is made for the Raspberry Pi 4B. The whole case is Aluminium.
The author marked this model as their own original creation.
