The NBX-10990 is a galvanized steel internal panel designed for use in NEMA enclosures and electrical boxes. It is manufactured from 16 gauge steel with a galvanized finish for corrosion resistance, featuring four 0.315 inch diameter mounting holes and 0.344 inch radius corners at all four places. The panel dimensions are 13.120 inches (A) × 11.620 inches (B) × 17.620 inches (C) × 16.120 inches (D), with a tolerance of ±0.039 inches (±1 mm). Each panel is supplied with four M5 × 10 mm truss head Phillips drive stainless steel machine screws for secure installation. This internal panel is commonly used in industrial control enclosures, electrical distribution boxes, and equipment housings where a durable, corrosion-resistant mounting surface is required.