For this product, no supplement of electrical source is required. Only sunlight will make it work. Economical, convenient and practical, its applications are in places of powerless, power-shortage, field, travel, and gift presentation, etc. It saves your worry of no dry battery or bad contact. This product uses the super-bright LED as lamp-houseAdopting superbright white LED as lighting source.It is very convenient and can be widely applied in camping, traveling,military factors and other fields.