You can conserve electricity and provide a lighted, safe environment at night by using the battery operated Mr Beams Motion-Sensor LED Stair Light. The device has a built in photocell that ensures that the LED will only be activated in darkness. Once activated, the LED will remain in a stand-by, low-glow mode. While in low-glow mode, the motion sensor is ready to detect movement, and once movement has been sensed, the LED will brightly illuminate the area immediately round it. If you prefer not to have low-glow mode enabled, a convenient switch has been built in that will allow you to disable this feature. As the sun rises or the location of the device becomes lit, the LED will shut off, extending the life of your batteries. As an added convenience, you can set the automatic shut-off time between 20 seconds or 1 minute. It can be mounted virtually anywhere you may need light, such as the stairway, bathroom, hallway or kitchen, just to name a few. This product is weatherproof, so it is versatile enough to be mounted outside your home on the front porch, back patio, or shed, and is perfect to light decks and docks. As a safety measure, the Mr. Beams Stair Light can be placed anywhere in or around your home where falls are a concern. The Motion-Sensor LED Stair Light requires the use of three C batteries for power, sold separately.