Siemens SITOP DC UPS Uninterruptible Power Supply, 21.5 → 28.5V dc Output, 15A. Input Voltage: 22 → 29V dc. Communications: Serial Port, USB. Length: 125mm. Width: 50mm. Depth: 125mm. Maximum Temperature: +60°C. Minimum Temperature: 0°C. Dimensions: 125 x 50 x 125mm. Weight: 450g. MPN: 6EP1931-2EC42