Kingston KTH-XW9400K2/4G DDR2 - 4 GB : 2 x 2 GB - DIMM 240-pin - 667 MHz / PC2-5300 - registered - ECC KINGSTON KTH-XW9400K2/4G PC2-5300P DDR2 667 4GB ECC REG KIT (2G x2) FOR SERVER ONLY FOR SERVE ONLY - NOT FOR DESKTOP SYSTEMS