Extension housing TR-004 with 4 USB 3 bays. QNAP's 2 Gen 1 RAID is unique in that which allows you to expand the storage capacity of not only your QNAP NAS but also Windows host systems Mac or Linux. Use it this way as DAS (Direct Attached Storage) and access its contents simply by connecting it to your system using the built-in USB 3 port. 2 Gen 1 Type-C and included USB Type-C to Type-A cable. TR-004 is equipped with four compartments for 3 5" hot-swappable SATA drives which support 3.5 and 2.5 inch hard drives as well as solid state drives 2 5 inches. Drive bays can be configured with hardware or software management in RAID 0 modes 1, 5 and 10, each providing performance data redundancy or a combination thereof. For those who do not require RAID Individual and JBOD modes are also available.