Distribution boxes can be broadly categorized by their voltage level, application environment, and primary function. The two most fundamental distinctions are between Low-Voltage Distribution Boards and Medium-Voltage Distribution Enclosures, often referred to as Ring Main Units. 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. There are two types: Manual Transfer Switch: Requires manual operation to shift load to backup power. Distribution. In this guide, we'll break down the 12 main types of distribution boxes in a way that's easy to understand. We'll chat about what each one does, where it shines, and then dive into how to choose the perfect box for your needs.