This HP 726724-B21 compatible 64GB () DDR4-2133MHz quad rank load-reduced ECC 1.2V 288-pin CL15 factory original LRDIMM kit 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.