NBB-Series UL/NEMA/IEC Boxes Bud Industries NBB-Series UL/NEMA/IEC Boxes meet NEMA 1, 2, 4, 4X, 12, and 13 and IEC529-IP65 requirements. Most of these gasketed enclosures have been tested and approved to UL508-4X specifications, with some being approved to UL50-4X. The outdoor versions are UL508-4X enclosures molded out of light gray PC/PBT blended plastic with a UL94-5VA flammability rating. The indoor versions are ABS plastic enclosures molded out of light gray material with a UL94-HB flammability rating. The UL508-4X enclosures are molded out of light gray ABS/PC blended plastic with a UL94-5VB flammability rating. Bud Industries NBB-Series UL/NEMA/IEC Boxes feature front doors with plastic hinges and snap-action latches. The doors are clear polycarbonate plastic with a UL94V-0 flammability rating.