4GB 2 X 2GB PC2-5300F 667MHz 240 pin DDR2 SDRAM ECC Fully Buffered FB DIMM Server Low Power Memory for HP Workstation XW8600 (PARTS-QUICK BRAND). Equivalent to HP Part Numbers: 397413-B21, 442823-B21,
Hynix 4GB 4G DDR2-667MHZ PC2-5300F 2RX4 ECC FB-DIMM Server Memory RAM Server Memory - Newegg.com
Server Memory For Hynix 4gb 4rx8 Ddr2 667mhz Pc2-5300f Fbd Ecc Fb-dimm Ram Eight - Rams - AliExpress
Avant 8GB PC2-5300F DDR2 FBDIMM 667MHz Server RAM Memory | eBay