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 select DiskStation solutions.. 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 systems within home, SOHO, and small business environments, the 4TB IronWolf 5900 rpm SATA III 3.5" Internal NAS HDD from Seagate is built to withstand 24x7 operations, or up to 180TB per year / 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. The IronWolf also has an MTBF rating of 1.0 million hours, a workload rate of up to 180TB per year, a non-recoverable read error rate of 1 per 10¹⁴, and 600,000 load/unload cycles. Protection is provided by a limited 3-year warranty.