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,
For original Kingston PC Memory RAM 2GB PC2 DDR2 4GB DDR3 8GB 667MHZ 800MHZ 1333MHZ 1600MHZ 8GB Memoria Module Computer Desktop|RAMs| - AliExpress
DUOMEIQI 4GB Kit (2 X 2GB) 2RX8 DDR2 667MHz DIMM PC2-5300 PC2-5400 PC2-5300U CL5 1.8v 240 PIN 5300U Non-ECC Unbuffered Desktop Memory RAM Module Compatible with Intel AMD System at Amazon.com
Hynix 1GB DDR2 RAM PC2-6400 240-Pin DIMM at Amazon.com