20 bulb led string lights for outdoors with timer and twilight sensorwarm white leds set off these 20 bulb string lights for outdoors with an atmospheric light the string lights are equipped both with a twilight sensor and with a timer six or nine hours this means that the string lights light up when it gets dark and then shine depending on the time set for six or nine hours this is repeated every day when darkness falls batteries not included 4 x aa they can be obtained separately