Check the listing for details. CyberPower CST135UC 1350VA 810W - Battery Backup Error Code. Color: Black, Condition: For parts or not working. Listed at 69.99 USD. Has a U countdown from 12-0 then restarts. Not sure if it has other problems. Sold AS-IS for parts with no returns. This CyberPower CST135UC battery backup is designed to provide reliable power protection for your devices. With a maximum power output of 810W and voltage compatibility of 1350VA and 120V, it is compatible with APC brand products. The microATX form factor and black color make it a sleek addition to your setup. It features audible alarm, surge protection, AVR (Automatic Voltage Regulation), and an LED display. The battery backup also has a number of outlets, including Mini-USB connectors. Please note that this item is intended for use with computers, tablets, and networking devices, and is part of the Power Protection, Distribution category.