All Dura-Line's smooth wall conduit meets or exceeds one or more of the following standards: ASTM F-2160, ASTM D-3035, ASTM D-2239, ASTM D-3485, NEMA TC-7, UL 651, UL 1990, Bellcore GR-356. Features include: usable as outer conduit or innerduct, flexible HDPE allowing gradual bends without special equipment, co-extruded with SILICOREUHF lining for longer cable pulls and higher speed jetting, continuous lengths/long reels, and cold-climate installability. Available in multiple sizes and colors; select SDR (including SDR 9) and other wall ratings and pull-tape options per product configuration.