Synology 5 Bay SATA Expansion Unit (Synology DX517) - Drive Bays: 5, AC Input Power Voltage: 100 V to 240 V AC, Power Frequency: 50/60 Hz, Single Phase, System Fan: 80 mm x 80 mm x 2 pcs, External Ports: 1 x eSATA Port, Applied Models: DS1517+; DS1817+; DS1019+; DS1517; DS1817; NVR1218