Review on GeeekPi Raspberry Pi 4B GPIO Expansion Board with Dual Fans, 5V DC and LED, Raspberry Pi 4B Heatsink Kit for Raspberry Pi 4 Model B, Raspberry Pi 3B+, 3B, Pi 2B, and Pi Zero by Jamie Masloski

Prior to this fan hat, the RPI was too hot to touch and would likely shorten its lifespan. Raspberries are slightly warm, not even remotely hot, with this double fan hat! Fits perfectly and doesn't interfere with the digital hat at all. I will be buying one of these for every RPI I have that uses a hat. The bonus is that the LEDs in this fan aren't too bright or obnoxious, and each fan turns on individually. Well done designers!