4GB KIT (4 x 1GB) For Dell XPS Desktop Series 210 (DXC061) 400 (DXP051) 410 (DXP061) 420 625 630 630i 700 (DXG061) 720 720 H2C. DIMM DDR2 NON-ECC PC2-6400 800MHz RAM Memory. Genuine A-Tech Brand. 4GB KIT (4 x 1GB) DIMM DDR2 NON-ECC PC2-6400 800MHz 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)