SDQ series dual power supply switch box has compact structure, reliable throwing and flexible configuration. It can be assembled with CB grade products or PC grade products according to users' requirements, and is widely used in the distribution network of primary and secondary loads with high requirements for power supply continuity, and is mainly used in the low-voltage power distribution systems of industry, medical, post and telecommunications, petroleum, coal, metallurgy, rail transportation, computer centers, ships, military equipment highways, airports, fire-fighting, civil buildings and other occasions as power, lighting, and fire-fighting. Fire and other dual power supply switching purposes. Comply with GB/T7251.12-2013 standard.