Review on 🔧 GeeekPi 2pcs Raspberry Pi 4 Quiet Fan: Efficient Cooling for Raspberry Pi 4 Model B/C, 3B+/3B/2B | 40x40x10mm Brushless CPU Cooling Fan Cooler in Black by Tylin Meyer

I have used these fans solely to cool my Raspberry Pi 4 with great results. So far they've delivered very consistent cooling with consistent reliability, and while you can hear the fans a little in a perfectly quiet room, the noise is imperceptible when there's other ambient noise in the room (computer fans, air conditioning, etc.). Room. Combined with two heatsinks (or with a GeekPi Ice Tower) and suitable 3D printed cases, I was able to keep temperatures under 30°C consistently. The only small limitation I found is that you are limited due to the number of available 5V pins and GND, so if you have multiple GPIO devices connected you may need to use fans that use alternative power supplies ( such as USB). Conclusion: Overall, these two packs are a great buy for two 40mm GPIO powered fans and are best for cooling your Raspberry Pi 4 in most cases, especially if you plan on using both fans.