QNAP TR-004 4 Bay USB Type-C Direct Attached Storage (DAS) with hardware RAID (Diskless)

Direct-attached storage device via USB Type-C for Windows, macOS and Linux
Use the TR-004 as external storage for NAS backup
Expand the capacity of your QNAP NAS
4 x 3.5 -inch SATA 3Gb/s (Diskless)
Hardware RAID supports RAID 0, 1, 5, JBOD, and individual disks
Includes a USB Type-C to Type-A connector cable
Lockable drive Bays.
NOTE: The TR-004 does not support the following: the TS-128, TS-228, TS-131, TS-231, TS-431, TS-431U, and NAS models that cannot be updated to QTS 4.3. 6 (or later). The TR-004 can only be used as an individual storage pool or volume on the NAS. Its storage pool/volume cannot be combined into the connected NAS. NAS applications cannot be installed on the TR-004. Drives can only be migrated from one TR-004 to another TR-004. The files and data stored on drives moved to/from a NAS (or another device) will not be recognized.