Raspberry Pi Armor Case Extension with fast attach wall mount

The Raspi3 and 4 really need cooling, and passive cooling is enough with the massive Armor Case housing wich you can get between 10 to 14 Bucks (thermal pads and screws included). Just google "Armour Case Raspberry Pi". There are specific models for the different Raspberries. Wifi still works.

But: if you want to have, let's say a realtime clock in your housing (or other tiny things connected with the GPIO), the Armor Case needs an extension (see remix source for the first try).
And here it