Dura-Line Smooth Wall HDPE Innerduct Conduit. 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. Co-extruded with SILICORE® ULF lining for longer cable pulls and higher speed jetting. Available in multiple sizes (1/2" to 6"), SDR ratings (including SDR 13.5), colors (including orange), and optional factory-installed PinPoint 18 AWG locate wire and Bull-Line pull tape (including 2500#). Continuous long reels (including 3000' reels documented by distributors) and sequential footage markings reduce installer joins and aid installation. (Source: Dura-Line product family pages and distributor product pages.)