This handy high-quality 15-amp outlet switch has 3 prongs, plugs into a standard outlet and allows you to plug any cord/device into it. The switch is mounted on the side - keeping it nicely away from other devices (or another switch) plugged into the other outlet.
The benefit of this switch is you can use it to stop the 120 volt AC signal powering devices and cords that you would rather have off at times, but don't want to go to the hassle of plugging in and out all the time. Plugging in-and-out can wear outlets out, wear cords out, and is more time consuming and more of a hassle than simply hitting a handy switch.
We use these switches to stop electric fields from getting on cords, and also to shut off energy-sucking devices like chargers and electronics - when they are not in actual use.