OWC 16GB DDR4 2133MHz PC4-17000 CL15 1.2V 288pin Server DIMM ECC Registered memory compatible with Lenovo System models x3500 M5, x3550 M5 (5463) and x3650 M5 (5462). 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. 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 Lenovo part numbers 46W0795, 46W0796, 4X70F28590, 4X70G78062 and 95Y4821.