argon raspberry pi 4 mini fan hat with built-in heatsink | on-off switch for the heatsink fan | fully controllable pwm hat | 2 pieces of rpi fan per pack argon forty the argon mini fan is the latest raspberry pi fan with heatsink that easily fits into any case. the 30x30mm fan only uses 12 gpio pins on the raspberry pi, allowing the use of other gpio pins for other projects. this rpi fan is also fully controllable with its switch. you can turn it on, off, or program it to turn on at a certain temperature when set to pwm mode.