The NAS offers three USB 2.0 ports for external devices and can be used as a print-server compatible with the standard network protocols of Windows or via IPP. Only printing is supported with all-in-ones.
You can also connect a compatible UPS. The compatibility list isn’t long and mostly includes products from APC. If there are a few NASes on your network, you can connect the UPS to one of them, which is going to be the server of this service, and connect the other NASes to it as clients.
The external ports will often be used to connect external storage devices, though. These can be ordinary flash drives as well as hard drives with multiple partitions. USB hubs are supported. Besides FAT32 and EXT2/3, the NAS can read and write files from/to NFTS partitions. You can format disk partitions in FAT32 and EXT3 using the NAS’s interface.
All connected volumes are visible as individual network folders. You can change their automatically created names like USB_HDD_1_2 to something more comprehensible and specify access rights. Your settings will hold after the device is plugged again (also to another port), which is very handy.
Data from connected flash drives can be automatically copied to a specified folder on the NAS. This may be useful for photographs, for example (all files from any USB port are copied into an individual folder named after the current date and time).