ECC REGISTERED UPGRADE: This type of memory is used in Workstations and Servers. It will NOT be compatible with standard desktop computers. Also, it cannot be mixed with UNBUFFERED -or- ECC LOAD REDUCED memory. OWC 64GB UPGRADE: Consists of 4pcs of 16GB DDR4 2400 PC4-19200 CL17 1Rx4 288-pin 1.2V ECC Registered DIMM Memory RAM Module Upgrade compatible with Cisco UCS model C240 M4. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. MAXIMIZE YOUR SERVER: With OWC's ECC Registered Server Memory, you will extend the life of your old infrastructure or save money when building a new one. Replacement for Cisco part numbers UCSMR1X161RVA and UCSMR1X161RVG.