The various components of a computer system such as the chipset, the graphics card and the hard drive can produce a large amount of heat while operating. This large amount of heat may be harmful for the proper functioning of the system. The heat sinks and the fans are responsible for dissipating this heat and maintaining the safe temperature limits. The most important factor which determines the selection of Heatsink Assembly is the processor type and its speed. Different processors have different operating temperatures. When selecting replacement heat sink and fan assebmlies for your higher speed processor, please make certain the specifications match orginal system purchase. The chassis type is also important as it defines the housing of the heat sink assembly and compatibility with the system. In order to buy the right fan and heatsink for your system, we recommend that you use the Service Tag look up feature in the Parts For Your Dell tool. This will allow us to identify the processor type and speed of your system and select compatible products for it. Refurbished Spare Parts are parts retrieved from Dell-branded systems that have been returned, some of which have never been used. All Dell refurbished spare parts are certified to comply with all original Dell factory performance specifications and come with a 90-day limited hardware warranty. Dells limited hardware warranty covers defects in materials and workmanship in your Dell-branded hardware products. For additional details on our warranty services, please visit www.dell.com/warranty.