Synology Expansion Unit RX1217/RX1217RP delivers an effortless solution for data volume expansion and data backup for Synology 2U RackStation NAS. With additional 12 drive bays, RX1217/RX1217RP seamlessly expands the storage capacity of the connected Synology NASon-the-fly. Synology RX1217/RX1217RP is backed with Synology's 5-year limited warranty.