Single-pole circuit breakers can effectively be locked out by these devices. By turning the screw, the lockout device pinches the switch and blocks it from movement. During maintenance work, this procedure makes sure that switches and therefore the machines are not accidentally turned on. The non-conductive circuit breaker lockout can be used universally on any standard single-pole circuit breaker. Thanks to the additional adapter, the lockout device can also be used on blade-type electric fuses.