C-Safe circuit breaker lockouts are constructed of rigid plastic. Available for either single or double pole circuit breaker lockout applications. The red color helps to identify from a distance. CB01 is a single pole lockout CB01 requires a switch breaker with a recessed hole in it. CB02 is a double pole lockout that requires the breakers to be connected with a cross bar for lockout application. CB03 is a single pole lockout that doesn't require a switch breaker with a recessed hole in it.