AddOn AM667D2DFB5/4G x2 HP 397415-S21 Compatible Factory Original 8GB DDR2-667MHz Fully Buffered ECC Dual Rank 1.8V 240-pin CL5 FBDIMM

These parts are FACTORY ORIGINAL Tier 1 modules (from either Samsung, Micron, Hynix, Infineon, etc.). You cannot buy a better module, and there is a good chance that it is an identical module you may get directly from the OEM. All AddOn modules are built to meet or exceed OEM specifications, and JEDEC standards. All memory modules come with a Lifetime warranty and are 100% guaranteed compatible for the appropriate systems it is intended for.