16GB KIT (4 x 4GB) Dell Precision Workstation Series 490 690 (1KW) 690 (750W) 690n (750W) R5400 R5400 Rack T5400 T7400 DIMM DDR2 ECC Fully Buffered PC2-5300 667MHz RAM Memory Genuine A-Tech Brand 16GB KIT (4 x 4GB) 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)