Master Lock Circuit breaker lockoutCircuit breaker lockout Lockout til sikringer. The Master Lock No. S2393 Universal Miniature Circuit Breaker Lockout Device locks out most miniature ISO DIN pin out circuit breakers throughout the world. The patented device fits breaker toggle and can be tightened using screwdriver. Device works with all Master Lock and American Lock safety padlocks and most hasps. Universal Miniature Circuit Breaker Lockout Locks out virtually all miniature ISO DIN