This HP® 501538-001 compatible 16GB DDR3-1066MHz quad rank registered ECC 1.35V 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.

• DIMM 16 GB bar will run multiple applications together and enhance your computer's performance
• 240-pin-pin DDR3 SDRAM interface synchronizes electrical and clock signals for an efficient data transfer rate
• 1066 MHz of memory speed makes your computer perform like an athlete