FeaturesAll finishes are UL classified as suitable as an equipment grounding conductor1/2 x 1 in steel channel welded rungs254 lb at 4 ft span, 163 lb at 5 ft span, 113 lb at 6 ft span, 83 lb at 7 ft span, 63 lb at 8 ft span capacity2 in H x 3/8 in W stringer dimension0.4 sq-mm UL cross sectional area0.271 sq-mm area, 0.145 cu-in Sx, 0.109 in^4 Ix design factors for (1) rail1/2 x 1 in rung size, 11 ga thick rung