OWC 16GB UPGRADE: Consists of a single 16GB DDR4 2400 PC4-19200 CL17 2Rx8 288-pin 1.2V Non-ECC Unbuffered DIMM Memory RAM Module Upgrade memory module compatible with QNAP models TS-873U, TS-873U-RP And TS-877. 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 numbers RAM-16GDR4A0-UD-2400 and RAM-16GDR4A1-UD-2400.