Outer protect layer are made of high density polyethylene engineering plastic, which has good anti-UV capability. Cover was coated with long-term UV-resistant polyethylene.Its surface has the advantage of smooth, wear-resistant and long service life.
There are meter marks on the protect layer of duct rodder, which can be used for measuring distance. Marks are printed by professional printing machine, which has the advantage of strong adhesion, clear writing, waterproof, anti-ultraviolet, it can be still clear even after using many times.