This chain of solar fairy lights is an environmentally friendly product as the lights are powered by the suns energy through the solar panel. During the day, the solar panel converts sunlight into energy, which is stored in the included rechargeable batteries. A sensor automatically switches the light on at dusk and off at dawn.The lights can be used for a multitude of outdoor and indoor applications including parties, barbeques and even Christmas tree lights.Supplied in a multicoloured chain that also flashes at random.A replacement battery is available (Order Code: N73JK). PLEASE NOTE: These batteries are solely for use in this solar light. UNDER NO CIRCUMSTANCES should they be charged in a battery charger or used in any electronic devices other than that stated.