User:RoySmith/drafts/Innerduct

Innerduct is flexible sheath used to enclose cables and protect them from damage. It is commonly used when running fiber optic cable through underground conduits originally designed for large-diameter telephone cables.

Several innerducts can be pulled through an existing conduit, providing protection from water, animals, and abrasion from rough conduit walls, as well as isolating one cable from the others.

Materials
HDPE