A-TECH 4GB STICK For Dell Optiplex 380 780. DIMM DDR3 NON-ECC PC3-8500 1066MHz RAM Memory. Genuine Brand. 4GB STICK DIMM DDR3 NON-ECC PC3-8500 1066MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Dell Optiplex. (See Compatibility List Below)