Key features massive scalability up to 180 drives hardware redundancy enhances system uptime rxd1215sas reliable scalable sas storage expansion unit rxd1215sas is a 12 bay storage expansion unit specifically designed to work with synologyrsquos rackstation rc18015xs when connected with rc18015xs it delivers the massive scalability and uncompromising resiliency that 247 businesses require massive scalability up to 180 drives up to fifteen rxd1215sas can be connected to the dual rc180