Synology 5bay Expansion Unit DX513 (Diskless) Internal HDD: 5x 3.5" or 2.5" SATA Expansion Port: 1(eSATA) Fan: 2x (80 x 80mm) Fan Noise Level: 30 dB(A) Power Recovery: Sync with the paired DiskStation (Default Mode) Power Frequency: 50/60Hz, Single Phase Power Consumption: 45.1 W (Access), 16.5 W (HDD Hibernation)