Product Detail 1GB Kit (2 x 512MB) DDR2 PC2-5300 . The "Crucial Technology CT2CP6464AA667 1 GB 512MBx2 240-pin DIMM DDR2 PC2-4200 CL=5 Unbuffered NON-ECC DDR2-667 1.8V" is best product for you. We recommended Crucial Technology CT2CP6464AA667 1 GB 512MBx2 240-pin DIMM DDR2 PC2-4200 CL=5 Unbuffered NON-ECC DDR2-667 1.8V