Synology 20TB DX517 5-Bay Expansion Enclosure Kit with Seagate NAS Drives (5 x 4TB)

Built to support on-the-fly volume expansion and local backups, the DX517 5-Bay Expansion Enclosure from Synology adds an additional five 3.5"/2.5" SATA drive bays to their DS1819+, DS1817+, DS1817, DS1618+, DS1517+, DS1517, DS918+, DS718+, DS218+, and NVR1218. Its drive bays are hot-swappable and screwless, and included is an AC power cord, an accessory pack, and an eSATA expansion cable. Protection is provided by a limited 3-year warranty.

Designed for use in 1-8 bay NAS environments within home, SOHO, and SMB environments, the 4TB IronWolf 5900 rpm SATA III 3.5" Internal NAS HDD from Seagate is built to withstand 24x7 operations, or 8760 hours per year. This 4TB drive has been equipped with a SATA III 6 Gb/s interface, a rotational speed of 5900 rpm, a 3.5" form factor, and a 64MB cache, providing users with an ample storage capacity and data transfer speeds of up to 180 MB/s. This IronWolf hard drive also has an MTBF rating of 1 million hours, 600,000 load/unload cycles, 1 in 10¹⁴ non-recoverable read errors per bits read, and a workload rate of up to 180TB per year.