the sel17 is a dual head, led emergency light, designed to reduce egress system cost and maintenance as well as improve reliability. adjustable, long lasting acculed's and a sealed nickel cadmium battery ensure the unit will function when a predetermined reduction of ac power is detected. patented ez hang feature facilitates quick and easy installation. universal j-box mounting pattern and keyhole slots. the unit is injection molded, and made from a high-impact thermoplastic. dual voltage input 120/240/277 vac. 5 year warranty.