Indoor boxes prioritize compact size, easy access, and neat fiber management for protected environments. Selecting between indoor and outdoor distribution boxes starts with the environment and compliance. Indoor units are suited for controlled spaces with low moisture and particulates, often rated IP20–IP40, while outdoor enclosures require IP65–IP68 or NEMA 3R/4/4X ratings to resist rain, dust, and. The primary function of a distribution box is to ensure the safe distribution of electrical power, but the design and features of indoor and outdoor distribution boxes differ. Below, we explain their main differences, applications, and how to choose the ideal option for your electrical project.