4GB Memory Upgrade for Dell Dimension XPS Gen 4 (G4) Desktop PC 4 X 1GB DDR2 NON-ECC PC2-4200 240 pin 533MHz DIMM RAM (PARTS-QUICK BRAND) Speed: PC2 4200 533MHz Form Factor: 240 pin DIMM Capacity: 4GB Total 4 x 1GB Warranty: Lifetime