Distribution boxes vary in shape and structure due to different usage scenarios and requirements, but the basic components include fuses, circuit breakers, SPDs, switches, bypass devices, various insulating materials, wires, bus bars, and other components. Home / blog / Ultimate Guide to Distribution Boxes (DB Boxes): Types, Components, Applications, and How to Choose the Right One For procurement professionals, electrical contractors, and project managers, choosing the right Distribution Box (DB Box) is a critical decision that directly impacts. What is a Distribution Box? A distribution box, or DB box, is a circuit breaker enclosure. It is a vital part and central hub of any electrical system. The hub distributes electrical power from a single input source to various circuits throughout a building.