Note: Please make sure that the anode and cathode of battery has been installed correctly. Please do not install 2 lights too close from each other. The lighting may cause the other one DOES NOT work. If you use Alkaline battery first and then change to zinc-manganese dry battery, the lights might not work as the zinc-manganese dry battery is shorter than the Alkaline battery. The sensor light might not work if you use the infrared heater in winter. The infrared will cause failure of the sensor. However, the light will get back to work in 30 minutes after turning off the heater. Enough Light Movements up to 5 feet away are detected in a wide 120 radius. So you automatically get light when you need it most. Provide enough light to make sure you never stumble in the dark. After 20 seconds of inactivity, the light will automatically switch off again. Specifications: Material: plastic Light Source: 6 LED 2835 Power: 0.6 watts Voltage: 36V Induction Time: 20S Power Supply: 3 AAA batteries (not included) Size: about 80mm x 80mm x 20mm