Symmetra RM UPS: SYRMXR4B4.
Symmetra LX UPS: use any combination of SYARMXR3B3, SYAXR9B9, SYARMXR9B9, or SYRMXR4B4. SYXR12 and SYXR4 cabinets are compatible only with the use of the DC cable adapter, SYOPT3, which is discontinued.
Please note: The maximum number of XR frames that can be supported by single phase Symmetra platform is 7. Symmetra LX systems with integrated XR cabinets can only communicate with 6 additional, external XR cabinets.