2GB 533MHz DDR2 ECC Fully Buffered CL4 DIMM Dual Rank, x8...Standard 256M X 72 ECC 533MHz 240-pin Fully Buffered DIMM (SDRAM-DDR2, 1.8V, CL4, FBGA, Gold). ValueRAM's 2GB (256M x 72-bit) PC2-4200 CL4 SDRAM (Synchronous DRAM) "fully buffered" ECC "dual rank" memory module. This module is based on eighteen 128M x 8-bit 533MHz DDR2 FBGA components. The module also includes an AMB device (Advanced Memory Buffer).