Illumination: Adjustable long lasting, efficient ultra-bright white LED lamp heads. One, 0.5 watt white LED per lamp head. Unique all inclusive lamp, reflector and lens assembly. Long-lasting, energy efficient Red LED exit sign illumination. Electrical: Dual 120V/277 voltage standard. Unique bi-color LED indicator light alerts occupant on battery condition (green-normal, red-check battery). 3.6V long-life, maintenance-free, rechargeable Ni-Cad battery(included). Internal solid-state transfer switch automatically connects the internal battery to LED board and LED lamp heads for minimum 90-minute emergency illumination. Fully automatic solid-state, two-rate charger initiates battery charging to recharge a discharged battery in 24 hours. Mounting: EZ-snap thermoplastic mounting canopy included - provides top or end mount. Universal K/O pattern on back plate for wall mount. Housing: Injection-molded, engineering-grade, 5VA flame retardant, high-impact, thermoplastic in white finish.