PEX-12 Series Air Insulated RMU is a completelyclosed system with all the electrified elements and switches sealed in stainless steel enclosure. It is not influenced by external environment so as to ensure operation reliability and personal safety and realize maintenance free. By selecting expandable bus, it is accessible to any combination, reaching full modularization. Expanded bus is completely insulated and shielded so as to guarantee high reliability and safety. It is able to offer industrialized automation solutions, to create concept of intelligent switch and minimum workload of field commissioning.