“small & fits pimoroni housing - cut the screws to fit on top of metal heatsink (but soldering or taping might be required to keep it from slipping off the pins.”
“Excellent fan for the Raspberry Pi 4 really drops the temp of your Pi when operating, so quiet, I love the Pi range because it is silent and this fan really complements this ethos.”
“Very easy and quick to assemble and install, even for the non-technical user. No extra tools required for assembly. Works perfectly, with almost zero noise when running. Only minor quibble: if you follow the instructions for the software exactly, it will be installed off of the user's home directory -- should probably add a step to move it into a more suitable location for services/daemons after download.”