4GB KIT 2 x 2GB Dell Precision Workstation Series 490 690 1KW 750W 690n R5400 Rack T7400 DIMM DDR2 ECC Fully Buffered PC2-5300 667MHz RAM Memory Genuine A-Tech Brand 4GB KIT (2 x 2GB) DIMM DDR2 ECC Fully Buffered PC2-5300 667MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Dell Precision Workstation Series. (See Compatibility List Below)