AddOn 4GB DDR4 SDRAM Memory Module - 4 GB (1 x 4GB) - DDR4-2133/PC4-17066 DDR4 SDRAM - 2133 MHz - CL15 - 1.20 V - ECC - Unbuffered - 288-pin - DIMM - Lifetime Warranty

IBM® 46W0809 Compatible Factory Original 4GB DDR4-2133MHz Unbuffered ECC Single Rank x8 1.2V 288-pin CL15 UDIMM