Xodus Innovations XL150D Dimmer Switch for up to 150 Watt Incandescent Bulb for Use with Lamps and Fixtures, White Polymer Full Range Manual Control Converts Any Lamp to a Dimmer For Standard Incandescent Bulbs up to 150 Watts Max Compact Size Fits in Most Standard Size Base Light Fixtures Installs in Minutes No Wiring Needed, Indoor Use Only Just screw into the light bulb socket of your lamp, whereupon you screw the light bulb into it which adds about 1 and 1/4 inch to the height of the bulb