Top Quality of the UPS POWER with good ups battery SURT6000XLI Smart-UPS On-LineAPC Smart-UPS RT 6000VA 230VAPC Smart-UPS On-Line, 4200 Watts / 6000 VA,Input 230V / Output 230V, Interface Port DB-9 RS-232, RJ-45 10/100 Base-T, Smart-Slot, Extended runtime model, Rack Height 3 UIncludes: CD with software, Smart UPS signalling RS-232..