Hiport 4GB RAM Memory For Dell Inspiron 660, 660S, 3847 Desktop (4GB DDR3-1600 PC3-12800 240-pin DIMM) Capacity: 4GB Form Factor: 240-pin DIMM Type: DDR3-1600 PC3-12800 (non-ECC) Chipset: 2Rx8 16c 1.50V CL11