2GB Kit 2 X 1GB DDR2 Memory for Dell Optiplex GX320 GX520 GX620 Desktop PC2-5300 240 pin 667MHz DIMM RAM (PARTS-QUICK BRAND) Speed: PC2 5300 667MHz Form Factor: 240 pin DIMM Capacity: 2GB Kit 2 x 1GB Warranty: Lifetime Brand: Samsung/3rd