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 memory. OWC 64GB UPGRADE: Consists of 4pcs of 16GB DDR3L 1600 PC3L-12800 CL11 2Rx4 240-pin 1.35V ECC Registered DIMM Memory RAM Module Upgrade Kit memory compatible with Supermicro SuperServer models 2027PR Series, 2027R Series, 2027TR Series, 2028UT Series And 4027GR Series. 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.