4GB KIT (4 x 1GB) For Dell Dimension 4700 5000 5100 5100C 5150 (DM051) 5150c 8400 C521 E510 / E510n E520 E521. 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 Dimension. (See Compatibility List Below)