Komputerbay 4x 4GB 240 PIN DDR2 PC2-5300F 667MHz CL5 ECC Fully Buffered FB-DIMM 16 GB With Heatspreaders ECC Fully Buffered (an FBDIMM will not fit into a standard DDR2 socket, and a DDR2 module will not fit into an FBDIMM socket) Capacity: 16GB Speed: PC2-5300F 667MHz 240-Pin DIMM Lifetime Warranty