Plastic distribution boxes are lightweight, corrosion-resistant, and often used in residential or light commercial applications. Distribution. now provides even more flexibility. The family is complemented thanks to new 5-row flush-mounted and hollow-wall distribution boards with up to 60 modules plus 10 MU reserve, which are also equipped with expandable KSK combin tion plug-in terminals as standard. Addition l cable holders enable tidy. Metal distribution boxes, made from galvanized steel, stainless steel, or aluminum alloys, offer superior mechanical strength, fire resistance, thermal stability, excellent heat dissipation, grounding capability, and electromagnetic interference shielding. It also needs to resist heat and tracking. Understanding its significance.