4GB STICK For Dell XPS Desktop Series 8500 8700. DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory. Genuine A-Tech Brand. 4GB STICK DIMM DDR3 NON-ECC PC3-12800 1600MHz 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)