SESX2B3Z 4GB Memory Expansion (2 × 2GB) X-Option, RoHS:Y 511-1151 2GB DDR2-667/PC2-5300 1.5V DIMM, RoHS:Y SESX2C1Z 8GB Memory Expansion (2 × 4GB) X-Option, RoHS:Y 501-7954 4GB DDR2-667/PC2-5300 1.8V FBDIMM, RoHS:Y SESX2C3Z 8GB Memory Expansion (2 × 4GB) X-Option, RoHS:Y 511-1152 4GB DDR2-667/PC2-5300 1.5V DIMM, RoHS:Y SESX2D3Z 16GB Memory Expansion (2 × 8GB) X-Option, RoHS:Y 511-1228 8GB DDR2-667/PC2-5300 1.5V DIMM, RoHS:Y QQ