Single Samsung 64GB DDR4-2400 ECC LRDIMM server memory module. Samsung M386A8K40BM8-CRC4Q, 64GB 4DRx4 PC4-2400T, CL17, 1.2V, 288-pin LRDIMM. Lenovo OPT 46W0841 / FRU 46W0842. Pulled from a working server and in good working order; ships in protective clamshell. For servers/workstations that support LRDIMM only — will NOT work in desktop PCs or laptops, and cannot be mixed with regular RDIMMs on most boards. Please verify LRDIMM compatibility with your system before buying.