2GB 533MHz DDR2 ECC CL4 DIMM...Standard 256M X 72 ECC 533MHz 240-pin Unbuffered DIMM (SDRAM-DDR2, 1.8V, CL4). ValueRAM 256M x 72-bit (2GB) DDR2-533 CL4 SDRAM (Synchronous DRAM) ECC memory module. The components on this module include eighteen 128M x 8-bit (16M x 8-bit x 8 Bank) DDR2-533 SDRAM in FBGA packages. This 240-pin DIMM uses gold contact fingers and requires .8V.