This Lenovo 57Y4427 compatible 8GB DDR3-1333MHz dual rank registered ECC 1.5V 240-pin CL9 factory original RDIMM is 100% guaranteed to be compatible with your system and to work right the first time. All of our server memory is built to strict JEDEC 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.

• 8 GB of memory to heighten your computer's performance
• DDR3 SDRAM interface synchronizes electrical and clock signals for an efficient data transfer rate
• Up to 1333 MHz speed with Registered signal for smooth computer performance