4GB KIT (2 x 2GB) For Dell XPS Desktop Series 200 (DXC051) 420 600 (DXG051) 630 630i 710 710 H2C 720 720 H2C One One 20. DIMM DDR2 NON-ECC PC2-5300 667MHz RAM Memory. Genuine A-Tech Brand. 4GB KIT (2 x 2GB) DIMM DDR2 NON-ECC PC2-5300 667MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Dell XPS Desktop Series. (See Compatibility List Below)