Crucial Ballistix 2GB kit (1GBx2), 240-pin DIMM, DDR2 PC2-6400 Memory Module - BL2KIT12864AA804 Storage Capacity - 2GB Technology - DDR2 SDRAM Form Factor - 240-pin DIMM Supply Voltage - 2.2V Memory Speed -- 800MHz DDR2-800/PC-6400