Qnap TS-451DEU-2G 4-Bay 1U depth NAS Enclosure - Intel Celeron J4025 dual-core 2.0 GHz processor (burst up to 2.9 GHz), 2 GB SO-DIMM DDR4 RAM (1 x 2GB, 2 x slots free, 8GB Max), 4GB Flash Memory, Drive Interface: 4 x 3.5-inch 6Gb/s, 3Gb/s SATA Hard Drives Bays, Hot-swappable,M.2 SSD Slot 2 x M.2 2280 SATA 6Gb/s slots, AES-NI encryption, Without Rail Kit (RAIL-B02), Connectivity: 2 x USB 3.0, 2 x USB 2.0, 2x 2.5GbE, 1U Rackmount, 100W single power supply