Steel electrical metallic tubing. Manufactured using the latest technology and protocols to ensure the highest quality. Features a proprietary smooth ID coating to ensure up to 20% faster wire pulling. The light-wall mechanical properties allow for easy hand bending on small sizes and a smooth bend on intermediate and larger sizes. Certification: UL-797,ANSI C80.3,NEC ARTICLE 358,NFPA 70:NEC 250.188(4)