I recommend for all PCs that are "closed" from side to side without ventilation other than a small front and behind, and which has only a cooler which brews the hot air in the housing! this little cable is used to connect two fans to a single socket! so you can set up a fan that draws air "fresh" outside the box, and another that ejects the warm air from inside the case, which will enable your PC has less heat and therefore that of your equipment for longer!
