DDR2 is the next step to higher performance DDR technology PC4200 240-pin 533 M Hz Suitable for dual channel when installed in pairs Only for motherboards with DDR2 support A95CFDDR2 DIMM 256MB 32MX64 533 M Hz PC2-4200A96CFDDR2 DIMM 512MB 64MX64 533 M Hz PC2-4200A97CFDDR2 DIMM 1GB 128MX64 533 M Hz PC2-4200