Planet Waves Circuit Breaker; cables have a built-in mute switch to save your equipment from loud pops and squeals when you change guitars with a live amp or PA system. When the button is pushed, the cable shorts while remaining plugged into your guitar, making on-stage guitar changes a snap. Once the cable is shorted, remove the cable from the guitar being used and plug the cable into the next instrument. Simply press the button again to re-activate the cable signal.