JHS Mini A/B Switching Pedal A good solid A/B box can be a guitarist's best friend. We make ours from a Hammond 1.5"x3.6" metal enclosure with high quality jacks and switch. We also include a dual color (red/green) LED to let you know by sight if your using A or B. This is very practical in a live situation. Here are the best uses for our handmade Mini A/B: - Instantly swap between two instruments - Perfect for switching tones on dual-amplifier rigs - Isolate your tuner from the signal chain, while achieving silent onstage tuning - Leave output unplugged for a convenient mute function This pedal is passive but requires standard 9V DC Negative power for the LED to function and it measures 3.6"x1.5"x1" .