4GB DDR3 Memory Upgrade for Dell Inspiron 660s PC3-12800 240 pin 1600MHz Desktop RAM (PARTS-QUICK BRAND) 4GB PC3-12800 DDR3 1600MHz 240 pin for Dell Inspiron 660s Capacity: 4GB Speed: PC3-12800 DDR3 1600MHz Form Factor: 240 pin DIMM Halogen Free; ROHS Warranty: Lifetime