Dusk to Dawn A19 LED light bulbs is equipped with an external light sensor that turns the lights on automatically when the night falls and turns the light off when dawn comes. Comes with E26 bases that are compatible with most fixtures, and the bulbs are available for outdoor use. It can be widely used for porches, garages, front yards, back yards, corridors, hallways, driveways, etc. Note: This dusk to dawn A19 bulb is Non-Dimmable.The dusk-to-dawn function only can be triggered by sunlight. Don't cover the photosensor with anything.