16GB ( 1x 16GB Module ) DDR4 2666 MHz ( PC4-21300 ) DDR4 DIMM ( 288-Pin ) ECC RDIMM ( Registered DIMM ) 1.2V - DDR4 Standard Voltage Compatible Equivalent for HP 835955-H21, 840756-V91, P07029-B21, P08274-001, P02890-B21, P05588-B21, Q2D31A, 870840-001, 868846-001, 840756-091 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