Lenovo 4GB DDR4 2133Mhz Non ECC UDIMM Memory (4X70K09920) Adding more memory increases system performance. This Lenovo 4GB DDR4 2133Mhz Non ECC UDIMM Memory are low power, high-speed operation memory that use DDR4 SDRAM devices, allows you to upgrade your system's performance and enhance its ability to run more programs simultaneously. Test-proven 100% compatibility listed for supported systems.