Fiberglass Square Tube, Material Fiberglass, Wall Thickness 0.25 in, Color Dark Gray, Inside Corner Shape Square, Outside Corner Shape Square, Outside Height 4 in, Outside Width 4 in, Inside Height 3 1/2 in, Inside Width 3 1/2 in, Overall Length 10 ft, Maximum Temperature 150 Degrees F, Resin Type ISOFR, Standards ASTM E-84, Tensile Strength 30,000 psi, Wall Thickness Tolerance +/-0.038 in, Type Square, Type Square Tube, Length Tolerance +/-0.125 in, Minimum Temperature -100 Degrees F