4GB ( 1x 4GB Module ) DDR3 1600 MHz ( PC3-12800 ) DDR3 DIMM ( 240-Pin ) ECC RDIMM ( Registered DIMM ) 1.35V - DDR3 Low Voltage Compatible Equivalent for HP 713981-S21, 713981-B21, 713754-071, 715282-001, A2Z49AA 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