4GB (4x1GB) Ram Memory Dell Dimension E520 E520N E521 E521N (MAJOR BRANDS) Could be Samsung, Kingston, Hynix, Smart, Corsair, Elpida, Micron, or Nanya Capacity: 4gb (4x1gb) - You receive 4 Sticks of the 1GB SDRAM DIMMs for a total of 4GB Warranty: LIFETIME WARRANTY WorldWide Shipping to most countries & USA