Solar Powered Outdoor Christmas String Light in White 37ft 100 LEDs Fairylights Powered by the sun, no electric wiring required; Energy-efficient, average run time is up to 10 hours after fully charged. Super Waterproof, suitable for indoor or outdoor using.; Safety with CE certificate. Automatic sensor activates after power is charged. (lights out in daylight, lights work at dusk automatically) Rechargeable battery, pre-installed behind the solar panel. Come with ground spikes/stakes for easy fixation.