Easy to use: Unplug lamp, Set dial for desired time. Screw unit with bulb into the lamp, place the dial to face natural sunlight. Use with translucent lamp shades or remove shade, turn power ON, to test ON/OFF cover upper left corner photocell area with your hand, the unit has 7-second delay from light to dark condition, for outdoor applications, control must be placed inside a rain-tight enclosure and not exposed to the elements.