Kingston 16GB (2 x 8 GB) 667MHz ECC Registered DDR2 PC2-5300 240pin DIMM for Servers P/N: KTH-XW9400K2/16G 2 x 8GB for 16GB Total DDR2-667 PC2-5300 ECC Registered CL 5, 1.8 Volt Server Memory - This will not work in standard Desktop machines