duct rodder/rods is filled 85% of fiberglass core is reinforced with high strength resin. Braided reinforcing wrap construction is add most duct/conduit, Surface Coating: Polypropylene, ABS747 Fiberglass Duct Rudders & Fish tapes, specially constructed to provide exceptionally high tensile strengths, whilst retaining flexibility. The 80% fill rate glass fiber core is reinforced with a high strength resin. A braided reinforcing wrap is added before the final polypropylene wear resistant protective coating is applied. The continuous rods range from 4.5mm to 16mm with lengths from 50m to 400m.