8GB ( 1x 8GB Module ) DDR3 1333 MHz ( PC3-10600 ) DDR3 DIMM ( 240-Pin ) ECC UDIMM ( ECC Unbuffered DIMM ) 1.35V - DDR3 Low Voltage Compatible Equivalent for HP 647658-081, 647909-B21, 664696-001, 647909-B212 High performance Memory RAM upgrade designed for Server/Workstation Systems All modules undergo quality assurance testing to ensure dependable and reliable performance Please verify the supported memory (RAM) specifications of your system prior to purchase to ensure compatibility A-Tech provides a Lifetime Warranty for all orders & offers complimentary United States based Tech Support before, during, & after your purchase