Komputerbay 4GB 2x 2GB DDR2 PC2 4200 533Mhz 240 Pin DIMM 4 GB CL 4 KIT Komputerbay 4GB 2x 2GB DDR2 PC2 4200 533Mhz 240 Pin DIMM 4 GB KIT Well Tested. Non-ECC Non parity Unbuffered SUPPORTS DUAL CHANNEL RAM Memory Technology: DDR2 SDRAM Memory Speed: 533 MHz