397413-B21 HP 4GB (2X2GB) PC5300F MEM MOD Memory Size: 4GB DDR2 SDRAM // Number of Modules: 2 x 2GB Memory Speed: 667MHz DDR2-667/PC2-5300 Signal Processing: Fully Buffered with ECC // Form Factor: DIMM Dual-rank x4 // 1.50V // Registered // Dual in-line memory module (FBDIMM)