Cambridge Resources has custom engineered state-of-the-art extruding technology to weave the very finest quality Support Webbing that meets or exceeds every industry standard. Cambridge’s 1.75 in Support Webbing registers a remarkable tensile strength of up to 440 lb. Nylon webbing duct support strap. Use to hang HVAC duct. 440 lb average tensile strength. 1.75 in x 50 foot roll.