Emergency Exit Sign with Battery Backup automatically turns on when power goes out to provide 90 minutes of emergency operation. Energy-saving LED light lasts up to 25 years. Consumes less than 2 watts and eliminates lamp changes. Sealed maintenance-free battery with fully automatic charger lasts up to 10 years. Exit sign offers rugged polycarbonate construction, 120/277 dual voltage operation and front and rear stencils with snap-out directionals. Mounts on ceiling, wall or other surface. U.L. listed. Products meeting New York City and city of Chicago specifications may be special ordered through customer service.