The HP 3TQ39AA is an 8 GB DDR4 2666 MHz 288‑pin DIMM memory module designed for desktops and workstations. It is ECC (error‑correcting code) supported and unbuffered (UDIMM), providing reliable performance and data integrity for systems that support ECC memory. It operates at standard DDR4 voltage (1.2 V) and is suitable for upgrading or replacing RAM in compatible enterprise or workstation systems.