"This Multi-Pole Circuit Breaker Lockout device from RS is a clamp-on device that is suitable for use with the majority of major multi-pole breakers that use a tie-bar. Produced from strong, glass-filled nylon with a stainless steel screw, this lockout device is suitable for 120 V to 277 V.Type = Multi-Pole Breaker LockoutMaterial = Glass-Filled Nylon"