ECC LOAD REDUCED 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 REGISTERED memory. OWC 64GB UPGRADE: Consists of a single 64GB DDR4 2133 PC4-17000 CL15 4Rx4 288-pin 1.2V ECC Load Reduced DIMM Memory RAM Module Upgrade compatible with Fujitsu PRIMERGY models RX2530 M1-L, RX2540 M1, RX2540 M1, RX2560 M1 And RX4770 M2. 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 Load-Reduced Server Memory, you will extend the life of your old infrastructure or save money when building a new one. Replacement for Fujitsu part numbers S26361F3843E618, S26361-F3844-E518, S26361-F3844-E618, S26361-F3844-L518 and S26361F3843E518.