4GB ECC DDR4 RAM, 2666 MHZ, UDIMM for TS-2483XU-RP, TS-1683XU-RP, TS-1283XU-RP, TS-883XU-RP, TS-983XU-RP, TS-1886XU-RP, TS-1673AU-RP, TS-1273AU-RP, TS-873AU-RP, TS-873AU, TS-h886, TS-h686