This Dell® A8661095 compatible 4GB DDR4-2133MHz single rank unbuffered ECC1.2V 288-pin CL15 UDIMM is 100% guaranteed to be compatible with your system and to work right the first time. Adding additional memory is the best way to increase the performance of your system. All our memory is built to strict JEDEC standards standards at one of the tier 1 facilities (Samsung, Micron, or Hynix). Our products are also guaranteed by federal law to not affect or void OEM warranties.