12-bay 3.5/2.5 SAS/SATA expansionEasily add 12 additional drive bays to Synology FlashStation or RackStation. Supporting both 2.5 and 3.5 SAS/SATA drives the RX1217sas is a flexible solution supporting on-the-fly volume expansion or serving as a local backup destination.Maximum reliability designDual power supplies ensure continuous service uptime. Easily replace defective drives with the hot swappable drive trays. Experience fast and secure rack cabinet installation with the optional sliding rail kit RKS1317.5 year warrantySynology's 5-year limited warranty provides hardware replacement and technical support via email and telephone services maximizing your enterprises' return on investment.Synology Replacement Service (SRS)Free next business-day shipping for replacement units. SRS expedite the process of replacing defective products and minimize service downtime.