An outdoor SF₆ circuit breaker is a high-voltage protection device (72.5 kV–800 kV) utilizing sulfur hexafluoride (SF₆) gas for superior insulation and arc quenching in harsh environments. Designed for substations and transmission networks, it interrupts fault currents efficiently, even under extreme weather. Key components include gas-filled interrupter chambers, robust enclosures (weatherproof stainless steel/aluminum), and spring/hydraulic operating mechanisms. SF₆’s high dielectric strength enables compact designs and high breaking capacity, ideal for critical grid protection. However, SF₆’s potent greenhouse effect drives innovations in gas recycling, low-emission seals, and hybrid alternatives (SF₆-N₂ mixtures). Compliant with IEC 62271 standards, modern variants integrate IoT sensors for real-time gas monitoring, enhancing reliability and lifespan. Despite environmental concerns, SF₆ breakers remain vital for high-voltage grids due to unmatched performance in fault interruption and durability.