This HP P00922-B21 compatible 16GB DDR4-2666MHz dual rank registered ECC 1.2V 288-pin CL19 factory original RDIMM is 100% guaranteed to be compatible with your system and to work right the first time. All of our server memory is built to strict JEDEC standards at one of the tier 1 facilities (Samsung, Micron, or Hynix). Our products are also guaranteed by federal law to not affect or void OEM warranties.