The mini single latching footswitch with polarity switch is the ultra compact pedal that gives you the ability to switch channels like clean/drive on your amp. Works with most amps like Marshall, Fender, Laney, etc.
The polarity selector switch lets you change the selection of the channel you want with your dual channel amp. ie. Pressing the footswitch selects the clean channel, change the selector switch and now when you press the button you will select the drive channel.
All you need is a TRS/stereo lead to connect it to your amplifier.