QNAP TS-253E 2-Bay NAS Enclosure designed for high flexibility and long-term support allows you to quickly expand your network storage capacity to support backups surveillance, virtual machines and much more. Two compartments 3.5"/2 5" support SATA III drives which can be configured in RAID 0 or 1 mode to improve speed or reliability. You can improve your productivity even further by installing up to two M cache drives. 2 2280 NVMe PCIe 3. 0. Storage can be further expanded by connecting expansion enclosures to two USB 3 ports. 2 Gen 2 each of which can transmit data at speeds up to 10 Gbit/s.