IBM strives to lead in the creation, development and manufacture of the industry's most advanced information technologies, including computer systems, software, networking systems, storage devices and microelectronics. And the worldwide network of IBM solutions and services professionals translates these advanced technologies into business value for the company's customers.This Power Supply is intended for 2nd and 3rd SSA or SCSI Back Plane (6-pks). An auxiliary power supply (#6549) must be added when the second and third 6-packs are installed. This power supply is capable of supporting a total of nine 4.5GB or 9.1GB SSA enabled hard disks on the second and third 6-packs combined.