9E15Ki Eaton Online Double Conversion 9E 15KVA / 12000W Combo: 1:1 and 3:1, In-Built Automatic Relay Bypass, Intelligent Power Software, 1 USB port + 1 RS232 serial port (USB and RS232 ports cannot be used simultaneously), 1 slot for Network-MS, ModBus-MS or Relay-MS cards, 1 Year Warranty