Model SGK-12kV fully enclosed fully insulated ring main unit (hereinafter referred to as "gas insulated switchgear") is a new type of medium voltage ring main unit developed by our company by absorbing foreign advanced technology. The automatic laser cutting machine, NC sheet metal processing center, automatic welding machine, SF6 gas automatic maintenance equipment, various advanced testing instruments and supporting advanced flexible assembly production line are used to control the production and management of the company, which provides an effective guarantee for the high quality and reliability of switchgear. The ring main unit adopts modular design, with its perfect unification of fixed type and flexible expansion, which is suitable for different applications and provides satisfactory technical solutions for different users. The adoption of sensor technology and the latest microprocessor-based protection device, together with advanced technical performance, simple and flexible assembly scheme, can fully meet the changing needs of the market.