12kV & Below Box-type Fixed Metal-enclosed Ring Network Switchgear

This is a type of Medium Voltage (MV) Switchgear designed for 3.6kV to 12kV power distribution systems. It is commonly referred to as a "Ring Main Unit" (RMU) in international markets, though this specific description ("Box-type Fixed") typically points to an Air Insulated (AIS) modular unit rather than a fully gas-sealed (GIS) tank. It serves as the critical "node" in a ring network, allowing power to be distributed to multiple users (e.g., a transformer or a building) while maintaining the ability to isolate faults without shutting down the entire grid.