ECC REGISTERED UPGRADE: This type of memory is used in Workstations and Servers. It will NOT be compatible with standard desktop computers. Also, it cannot be mixed with UNBUFFERED memory. OWC 16GB UPGRADE: Consists of a single 16GB DDR4 2666 PC4-21300 CL19 2Rx8 288-pin 1.2V ECC Registered DIMM Memory RAM Module Upgrade memory module compatible with QNAP model TS-2888X. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. MAXIMIZE YOUR SERVER: With OWC's ECC Registered Server Memory, you will extend the life of your old infrastructure or save money when building a new one. Replacement for QNAP part numbers RAM-16GDR4ECK0-RD-2666 and RAM-16GDR4ECT0-RD-2666.