The 3C Wireless Motion Sensor LED Stair-Lite uses new LED technology to provide safe bright light anywhere you need it without connecting any wires. The light uses 3 C cell Alkaline batteries (not included) and will run for more than 1 year without changing batteries (based on average use). The Wireless LED Stair-Lite uses a sophisticated motion sensor coupled with a photo sensor and variable timer and brightness control. The LED Stair-Lite will only turn on when it is dark and only when motion is detected. The light turns itself off automatically after 30 seconds or 2 minutes. These features ensure long life, and energy efficiency for this light. The 3C Wireless Motion Sensor LED Stair-Lite comes complete with mounting bracket and hardware for easy installation.