Third-party verified to UL 508A and UL 50 standards — ready for NEC-compliant installations across industrial, commercial, and utility applications. From UL type electrical boxes to UL junction boxes, Polycase's UL Listed enclosures also offer a wide range of sizes, material and styles to choose from. Safety and reliability with trusted testing and certification for low- and medium-voltage distribution equipment. Learn. Product advantages: ◾all types designed for fast installation of PCBs and terminals ◾RAILTEC C: for PCB terminal blocks, plug headers and front connectors; optional frame for additional PCB position; front panels and lids in different versions; 1 to. What sets us apart is our extremely low lead times, desire to make customs and our vast selection of finished goods inventory.