The Raspberry Pi 4 has a fan now - the Case Fan | Jeff Geerling
Amazon.com: Aokin for Raspberry Pi Cooling Fan DC 5V/3.3V Brushless CPU Cooling Fan with Screws for Raspberry Pi 4 B, Pi 3 B+, Pi 3 B, Pi 2 B, Pi 1 B+,
5V Cooling Fan
Raspberry Pi Dual-fan Cooling Expansion Board With LED Compatible With All Types Of Raspberry Pi Pins
Miniature 5V Cooling Fan for Raspberry Pi (and Other Computers) : ID 3368 : $3.50 : Adafruit Industries, Unique & fun DIY electronics and kits
PIMORONI Fan SHIM for Raspberry Pi 4 – Vilros.com
5V Cooling Fan
Argon Fan HAT for Raspberry Pi 3B/3B+/4B - PiShop.us
Raspberry Pi 4 Case Fan - PRT-17368 - SparkFun Electronics
Smart Fan HAT the Best Cooling Solution for Raspberry Pi
Amazon.com: GeeekPi Fan Hat for Raspberry Pi 4 Model B, PWM Fan GPIO Expansion Board with 0.91inch OLED Display for Raspberry Pi 4B/3B+/3B/2B : Electronics
Miniature 5V Cooling Fan for Raspberry Pi (and Other Computers) : ID 3368 : $3.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Miniature 5V LED Cooling Fan for Raspberry Pi (30mm) | The Pi Hut
Cooling fan for Raspberry Pi 5
Raspberry Pi OS Fan Control - Embedded Computing Design
Raspberry Pi 4 7mm Embedded Heatsink with Cooling Fan (P165-A) – Geekworm
Argon Fan HAT – Argon 40 Website Store
Low-Profile CPU Cooling Fan for Raspberry Pi 4B/3B+/3B, with Aluminum Alloy Bracket
CanaKit Fan for the Raspberry Pi 5
KKSB Raspberry Pi 4 High Performance Cooler with PWM Fan — KKSB Cases
Amazon.com: for Raspberry Pi Fan, 4Pcs for Raspberry Pi Cooling Fan Brushless CPU Cooling Fan Heatsink Cooler Connector Separating One-to-Two Interface 3.3V 5V for Raspberry Pi4 Pi3 B+, Pi 3, Pi 2,
Amazon.com: Raspberry Pi 4 Fan, iUniker Raspberry Pi Cooling Fan 30x30x7mm Brushless CPU Cooling Fan for Raspberry Pi 4 Model B, 3 B+, Pi 3, Pi 2, Pi 1 B+, RetroFlag NESPI Case(2-Pack) : Electronics
Amazon.com: Raspberry Pi 4 Model B Aluminum Case with Dual Cooling Fan Metal Shell Black Box for RPI 4B (with Dual Fan) : Electronics
SC1148 Raspberry Pi | Fans, Thermal Management | DigiKey