Product Detail Sold Individually . The "Kingston - Memory - 2 GB - DIMM 240-pin - DDR2 - 533 MHz / PC2-4200 - 1.8 V - unbuffered - ECC" is best product for you. We recommended Kingston - Memory - 2 GB - DIMM 240-pin - DDR2 - 533 MHz / PC2-4200 - 1.8 V - unbuffered - ECC