4GB 2 X 2GB PC2-5300F 667MHz 240 pin DDR2 SDRAM ECC Fully Buffered FB DIMM Server Low Power Memory for HP ProLiant xw460c Blade Workstation (PARTS-QUICK BRAND). Equivalent to HP Part Numbers:
Kingston 2 GB (1 x 2 GB) 200-pin 667MHz DDR2 SDRAM at Amazon.com