Increase the available space without purchasing a new QNAP. Adapters (QDA) for 2 discs (2.5", M.2 SATAIII, M.2 PCIe NVME) in a single bay. External drives (Qulala) for direct connection and RAID protection (TR Series). Thunderbolt2 (TX) or USB 3 Gen1 5Gbps (UX) connection disk boxes to the main QNAP. QNAP's 1 bay/disk recommended only for remote safety replicas via WAN.