Komputerbay 4GB (2x 2GB) DDR2 PC2-6400F 800MHz ECC Fully Buffered 2Rx4 FB-DIMM (240 PIN) w/ Heatspreaders for Apple MAC computers ECC Fully Buffered (an FBDIMM will not fit into a standard DDR2 socket, and a standard DDR2 module will not fit into an FBDIMM socket) Capacity: 4GB For Apple Mac Pro (8-core) Desktop Speed: PC2-6400F 800MHz 240-Pin DIMM Lifetime Warranty