In SF6 gas circuit breakers, the extinguishing of the electrical arc and insulation are achieved using SF6 gas. The circuit breaker has been tested in accordance with IEC 62271-100 standards. Circuit breakers have a puffer-type arc extinguishing mechanism. The contacts are immersed in SF6 gas, ensuring maintenance-free operation throughout the electrical life of the circuit breaker. The operating mechanism is of the energy storage type, and the closing operation is carried out by charging the closing spring. Opening time is 0.3-5 seconds, and the closing time is 3 minutes. It is suitable for reclosing with a rated cycle of operation.