Synology RX1217sas delivers an effortless solution for volume expansion and data backup for Synology FlashStation/RackStation by adding 12 SAS/SATA drive bays on-the-fly. Synology RX1217sas is backed with Synology's 5-year limited warranty. Connecting to a Synology FlashStation FS3017 requires the optional FS3017 Expansion Card FXC2017 to be installed on the host device.