OWC 16GB UPGRADE: Consists of a single 16GB DDR4 2666 PC4-21300 CL19 2Rx8 260-pin 1.2V ECC Unbuffered SODIMM Memory RAM Module Upgrade memory module compatible with QNAP model TS-h973AX. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. EASY INSTALLATION: In Most Cases, Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for Help. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. Replacement for QNAP part number RAM-16GDR4ECT0-SO-2666.