4GB Kit 2 X 2GB DDR2 Memory for Dell Optiplex 160 330 360 740 745 745c 755DT 755MT 755SFF 760DT 760MT 760SFF 960 FX160 GX520 GX745 GX755 SX280 Desktop PC2-6400 240 pin 800MHz NON-ECC DIMM RAM (PARTS-QUICK BRAND) Speed: PC2 6400 800MHz Form Factor: 240 pin DIMM Capacity: 4GB Kit 2 x 2GB Warranty: Lifetime