Qnap RAM8GDR4ECP0UD2666, 8GB, DDR4 SDRAM, 1.20 V, Speed 2666 MHz, DDR4-2666/PC4-21333, ECC, Unbuffered, 288-pin, FF DIMM, Compatibility QNAP TS-983XU Enterprise NAS Server. These memory modules were designed and manufactured to ensure maximum performances in high end systems. Delivers superior quality, performance, and maximum compatibility with the computing systems.