Simple case for Raspberry Pi 4 with a mount for a 40mm Noctua Fan (Noctua NF-A4x10 5V) and space to put heatsinks on the Pi if you need them or would like to. 

This specific fan works with the Raspberry PI GPIO pins below and the cable is routed to land right below the 5v pins (which are Pins 2 and 4). You'll need to use the included 3pin to 2pin adapter that comes with the fan provided by Noctua. 

Noctua NF-A4x10 5V 40mm Fan - https://a.co/d/b1GMNmp 

The Raspberry Pi 4 sits on 4 standoffs where the screw holes on the board are and uses M2.5x8mm screws. Top piece connects with the 2 Latches on the top and snaps into the bottom holes. The fit together is rather tight so it may be a bit hard to pair together at first. 

M2.5x8mm Screws - https://a.co/d/7mxdmg9