SBK SafeRing ring unit (IEC) SafeRing is a SF6 gas insulated ring main unit for secondary distribution network. SafeRing has a variety of combination types, it is suitable for most applications switch occasions in distribution networks. Safering is a completely sealed system, all its live parts and switch closed in the inner shell of stainless steel. Sealed in stainless steel body in constant pressure conditions to ensure the operation reliability and safety, and achieve a maintenance-free. Safering has provided two options for the protection of transformer: Load switch fuse combination and circuit breaker with relay protection. SafeRing can also provide integrated remote control and monitoring systems.