A killswitch is a momentary switch, that when pressed, stops signal from going out of the guitar and going into the amp. Basically, when the button is pressed, there is no noise. Les Paul players usually achieve this effect by setting one pickup's volume to zero, and switching back and forth between pickups, creating a shuttering effect. However, this cannot be done on a Strat., since there is only one volume potentiometer.

Famous killswitch users include Buckethead and Tom Morello of Audio Slave.