A low profile device that assures lighting is OFF when sufficient daylight is available thus saving precious energy dollars. The light sensor (Model ELS-1) is placed about 3 feet from window or incoming daylight. When daylight level falls below the footcandle setting (user selectable), electrical lights will turn ON. When daylight level goes above the footcandle setting, electrical lights will turn OFF. 30 second delay prevents lights from turning on due to a passing cloud, etc. Adjustable timer for delayed turn-off in 3-15 minutes. Manual override provision in the unlikely event of system failure. Controls Fluorescent and Incandescent Lighting Systems. For use in Office, Classroom, Conference Room, Lavatory, Motel, Lobby, Drafting Room, Retail Display Area, Corridor, Warehouse.