Designed and manufactured to us navy spec mil-f-16377, Lanterns are made of yellow high impact glass filled polyester resin and are virtually indestructible. Lanterns require (@) 6 volt spring type batteries. (not included). Model SMY100-2 is portable with a built in carrying handle and has t mtg. bracket. Model SMY101-2 includes a 115v ac relay and 10 feet of power cord. When connected to a 115v power source the relay is energized and the sealed beam is off. When power is lost the relay de-energizes and the beam lamp comes on providing a powerful emergency light