Simply plug the PowerOut into any 120V outlet or power strip When the power fails, the PowerOut emits a pulsing alarm, about as loud as a conventional alarm clock At the Same time, the PowerOut illuminates a super bright LED to provide safety lighting The PowerOut can be removed from the outlet and the three-position switch set to “LIGHT” position, silencing the alarm and the super bright LED will provide up to six hours of portable lighting Set of 2 Reliance Power Out 100 lumens White LED Flashlight