Full Details on Amazon.com : http://www.amazon.com/gp/product/B00AZ3UBVK?tag=tsukuyomi-208GB (2x4GB) Memory RAM DIMM Compatible with Dell Optiplex 790 DDR3 DIMM240PIN DIMM DDR3-PC10600 NON ECC DDR3-PC10600 PC3-1333MHZ 2PCS KIT