Sulphur Hexaflouride(SF6) circuit breaker.

• Sulphur Hexaflouride gas is used as arc quenching medium.
• SF6 is an electro-negetive gas hence it has a strong tendency to absorb the free electrons.
• This breaker is opened at high pressure flow of SF6 gas and arc is struck between them. 

Fig: SF6 Circuit Breaker