Sensor provides automatic ON/OFF based on ambient lighting * Is energy-efficient, uses approx. 1W of electricity - No bulbs to replace * Saves space by eliminating the need to use an outlet for a plug-in night light * Reduced depth of SmartlockPro Slim GFCI makes it easier to install in any electrical box, even shallow ones * Automatically tests the GFCI every time the RESET button is pushed in. The GFCI will not reset if the GFCI circuit is not functioning properly