HPE 726722-B21 is a HP 32GB (1 x 32GB) Quad Rank x4 DDR4-2133 CAS-15-15-15 Load Reduced Memory Kit. When you choose HPE DDR4 SmartMemory, you get great performance, reliability, and efficiency that provides the compatibility, capacity and bandwidth you need to productively manage your expanding workload with the HPE ProLiant Gen9 server, Apollo Family, Synergy and Blade Systems. The quality and reliability of DRAM are more important now than ever, as data center trends such as server virtualization, cloud computing, the use of large database applications, have all increased the need for higher capacity memory with greater uptime. HPE SmartMemory goes through rigorous qualification and testing processes that unlock extended memory performance features available only with Hewlett Packard Enterprise Gen9 servers. This extensive testing ensures that HPE server memory is completely compatible with and optimized for HPE servers.