Synology DX213 Diskless System Expansion Unit for Increasing Capacity of the Synology DiskStation Form Factor: 2-Bay HDD Interface: 3.5 or 2.5 SATA(II) X 2 (hard drives not included) Power: 100-240 VAC 50/60Hz Power Consumption: 21W (Access), 6W (HDD Hibernation) Temperature: Operating Temperature: 5 to 35 degree Storage Temperature: -10 to 70 degree Humidity: 5-95% R.H Dimensions: 8.88 x 6.5 x 3.94 Weight: 1.92 lbs. Package Contents: DX213 Main Unit User's Guide Assembling Kit AC Power Cord AC Power Adapter Expansion Cable