The Royal Pacific REL14WH Two Head Emergency Light is a completely self contained unit that features dual 120/277 voltage adjustable lights. This light can be mounted on either a wall or ceiling. The light"s housing is made of a high impact thermoplastic which is flame retardant. Also features an integral recharging system, fully automatic operation, a momentary test switch and 31 lm output. Comes with a limited 5-year manufacturer"s warranty. The internal rechargeable back-up battery has an expected 10-year battery life. The battery is protected from deep discharge by automatic low voltage disconnect circuitry. Whenever normal AC current fails, the internal solid state transfer switch automatically connects the internal battery to the fixture to keep the sign continuously lit for at least 90 minutes. Unit is UL listed for damp locations. Operating temperature ranges from 10-Degrees C (50-Degrees F) to 40-Degrees C (104-Degrees F).