In order to power the PCP25 pump, an extension cord is used with an adapter plug. The adapter plug connects to the back of the PCI transfer bracket which in turn is powered by a PSU. By removing four hex screws reveals the internal configuration of the Xice ExternalCool EC900/H unit. The unit has been designed to act as a passive radiator and unlike traditional water cooling kits does not use any fans in the process. The EC900 works by using convection and natural ventilation which is solely based on air movement for cooling. As heat is drawn away from the CPU to the xpk CPU Heatsink, the heated water is transferred into the EC900 unit. The water travels through 10m worth of tubing where the ventilation openings at the top and bottom of the unit remove the heat and transfer it into the air. The cooled water is then transferred out of the EC900 and back to the PC where the cycle repeats itself. One point to note is that the success of passive cooling is dependant on the environment and ambient temperature. Consumers in heated environments will more than likely suffer performance loss since the process of passive cooling takes much longer without the use of cooling fans.