Critical systems should ideally be connected to some form of backup power in the event of a blackout, power surge or brownout. A fault at the grid may drop the voltage at the mains, which could cause some systems to shutdown, reset, lose data or worse, resulting in thousands of dollars of damage (both material and immaterial). These line interactive units give you a good balance between real time system protection and power redundancy when mains electricity is down or experiencing reliability issues. During mains voltage sags both units will deliver a steady voltage, keeping critical systems running properly. For a total power blackout the units can keep your systems running long enough to save important data or cleanly shutdown connected devices. Other important features include an auto shutdown when no load is detected, audible alarms for low battery, self diagnosis on boot, and intelligent battery management.Both models feature an easy to read LCD which displays battery and load values as a percentage and input/output voltages.