This Pro-Elec Maintained LED Emergency Exit Sign, Wall-Mounted offers constant illumination for public spaces where the exit may not be immediately familiar to those present. In the event of a power failure this emergency light will shine for three hours. You also have the choice of installing this as a non-maintained emergency light which will only light up if the power fails - a better option for office spaces where staff are familiar with the layout. What's more, you can change the legend to a different sign (legend pack sold separately). The 26 ultra-bright white LED ensure this 4.5W emergency exit sign is continuously observable to the people in the room - it delivers 40-lumens of light, to be precise. Order this Pro-Elec maintained LED emergency light today!