The OEM Master Lock 506 Safety Lockout is designed for effective lockout of circuit breakers. It features a durable, patent-pending Grip Tight design and is constructed from powder-coat steel and reinforced polymer, ensuring reliable operation in harsh environments. This set includes two lockouts, one for 120 volt and another for 240 and higher voltage circuit breakers, and is compatible with all American Lock and Master Lock safety padlock shackles and lockout hasp diameters.