8GB ( 1x 8GB Module ) DDR3 1866 MHz ( PC3-14900 ) DDR3 DIMM ( 240-Pin ) ECC RDIMM ( Registered DIMM ) 1.5V - DDR3 Standard Voltage Compatible Equivalent for HP 731761-B211, 731761-S21, 731657-581, 731761-B21, 731657-081, E2Q94AA, 735303-001 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