Dura-Line Smooth Outside Wall HDPE Conduit with internal longitudinal ribs is made to Industry Standards for Power and Communications Applications. It can be installed using open trench methods, HDD (Horizontal Directional Drilled) Plowed, or pulled into conduit. There are also versions available for aerial applications. With optional SilicoreTM Permanently Lubricated Lining, inside ribbed duct can be maximized for greater pulling and jetting distances, reducing the coefficient of friction over standard HDPE conduit. The ribs help direct airflow around the cable during cable jetting installations, and help minimize contact with the duct wall that reduces friction during cable pulling. Inside ribbed duct is available up to 6 diameter conduit.