Easy-to-install 2-by-4-foot LED panel with constant power emergency backup. Integrated maintenance-free NiCd battery backup provides 90 minutes or more of lighting during power outages to comply with the NFPA Life Safety Code. The UL-listed backup system makes the system UL 924-compliant. Push-button LED-illuminated test switch (supplied with labeled white mounting plate) enables easy compliance with scheduled testing requirements. System is fully charged in 24 hours. Soft, even lighting with no flicker. Dimmable with 0-to-10-volt dimming. Up to 5000 lumens or more with just 50 watts of input. Color rendition index (CRI) of more than 80. 3000K, 4000K or 5000K color temperatures. Ten-year warranty. Designed for 50,000-hour lifetime. 120-volt to 277-volt.