Distribution boxes are at the heart of safe and organized electrical systems—whether in residential, commercial, or industrial settings. But how do you choose the right one for your application?A distribution box, commonly referred to as a D-box, is a concrete, plastic, or fiberglass structure that serves as a junction point for wastewater from the septic tank before it flows into the drain field. It typically integrates overcurrent protection, residual-current protection where mandated, and. Types, Uses & How to Choose A distribution box, also known as a power distribution box or electrical distribution box, is used to distribute electrical power safely to multiple circuits. Main Breaker: Governs the full extent.