Polycarbonate and metal are tough. They protect the inside parts from harm. For wet or salty places, pick stainless steel or thermoset plastics. A distribution box is very important. The Engineering Pros of Plastic High-grade polymers, such as industrial ABS or polycarbonate, provide notable manufacturing benefits. This characteristic eliminates the need to earth the physical chassis. weather proof junction box is an indispensable part of the power system, and the distribution box housing is a key part to protect the distribution equipment and ensure the safety of personnel. weatherproof outlet box Housing Selection Guide 1.