Developed by NEMA Polymer Raceway Products Technical Committee, NEMA TC 13-2014 Electrical Nonmetallic Tubing standard serves as a tool for ENT manufacturers to check that their products are compliant with UL 1653 prior to submittal to UL for product listing. Standard covers materials, dimensions, and physical properties for ENT. Performance requirements for new trade size 2½ ENT have also been incorporated into this version.