No fears of darkness
5 in 1 ac/dc 40w lonen rechargeable led bulb: the intelligent led bulb for both emergency & regular use works on both standard ac power and also on in-built rechargeable battery (dc power). it is power saver convenient. equipped with two dc operation ways: light up/ light off with finger touch or receptacle mounted. suitable for home use or outdoor use.emergency function: with grid power on, the led bulb works as ordinary bulb while the in-built battery is being charged. when power fails, it converts automatically from ac to dc and the central led bulb lights up and can light on for 4.5 hours when fully charged.