Review on Raspberry Pi 4 Fan Quite: 4Pcs DC Brushless Cooling Fan 30Mm LED Heatsink Cooler Radiator Connector Separating 1 To 2 Interface 3 by Seth Gibbons

Very cheap and good mod for your Raspberry Pi! I have 3 installed on my 3b+/4 models. The fans have reduced my Pi's average operating temperature by 10-20 degrees Celsius. You can check the temperature of your Pi with the following command "/opt/vc/bin/vcgencmd Measure_temp". The red wire goes to pin 4 and the black wire goes to pin 6 (see attached picture). At $12.50 inclusive of tax for a four-pack, it was a no-brainer and I will be buying again when I've completed my Pi collection.