APC ATX 4000 Power Supply SUA5000RMT5U Output Power Capacity 4000 Watts / 5000 VA Control panel LED status display with load and battery bar-graphs and On Line : On Battery : Replace Battery : Overload and Bypass Indicators Interface Port(s) DB-9 RS-232,RJ-45 10/100 Base-T,USB Audible Alarm Alarm when on battery : distinctive low battery alarm : configurable delays Surge energy rating 540 Joules Form Factor5U Tower/Rack Mountable