About ProPOW LED Dusk to Dawn Bulb Security Sensor Light Bulbs 1.Dusk to dawn LED bulbs no UV,no lead,mercury and other pollution elements. 2.The sensor light bulbs are particularly useful for outdoor/indoors lights when you're away from your house on vacation or you are gone overnight--they automatically on/off, enhancing physical security. Convenient Outdoor Automatic Light Bulb 1.Automatically turn on and off:Automatically turn on at dusk(<15LUX),automatically turn off at dawn(>30LUX). 2.You don't have to think about turning the outdoor lights on at night anymore! Energy Saving(40 Watt equivalent) The LED dusk to dawn lights bulb go on at dusk and off at dawn, which means some savings on electric bill.