Synology prefers to paint its professional NASes black. The DS509+ follows the same trend, its case being matte black on all sides, save for the bottom and back panel. The device is rather large at 22x20x17.5 centimeters, but that’s natural for a 5-disk model.
The front panel is made from robust black plastic. Most of it is occupied by the HDD bays which support hot swapping and can be locked with a key. Above the bays there are four indicators and a Power button with integrated LED. The indicators help you learn the status of the device, the connection and activity of its network interfaces. At the top of the bays there are a couple of status indicators for each HDD.
The DS509+ does not have a dot matrix display which is often installed in modern NASes.
The casing and the chassis of the device are made from metal and seem to be robust and reliable.
At the back panel you can find two 80x25mm cooling fans (SUNON KDE1208PTV3) and connectors: power connector, two LAN ports with indicators, two USB 2.0 ports, one eSATA port and a serial port. There is also a Reset button and a Kensington security slot here.
Note that there are only two USB ports here, both at the back panel. Perhaps that’s not crucial for a SOHO device, but opponent products can offer up to five USB and a couple of eSATA ports.
The quality of manufacture is overall very high.