Adafruit Official Raspberry Pi 4 Case Fan & Heatsink is compatible with the Raspberry Pi 4 and the Raspberry Pi 4 Case. It's designed to push the performance of the Pi, and for overclocking. It keeps the Raspberry Pi 4 at a comfortable operating temperature even when under a heavy load. It has a mini heatsink that goes on top of the CPU and a fan that clips into the official Raspberry Pi 4 case.
Fits perfectly into Raspberry Pi 4 Case lid - Note that this item doesn't come with a Case, you need to purchase that separately
Temperature-controlled fan delivers up to 1.4CFM of airflow over the processor memory, and power management IC
18mm x 18mm x 10mm heatsink with self-adhesive pad improves heat transfer from the processor