... *41mm back to back 41*41mm, 41*62mm,41*82mm,and so on2)Thickness:1.5mm, 1.8mm,1.9mm,2 ... .0mm, 2.3mm,2.5mm ,2.7mm,3)Length:10 and 20 feet(3m,5.8m,6m ),special length are available ... steel or SS304 or SS3166)Surface Treatment:HDG(hot dipped galvanized ),Pre-galvanized,Cold-galvanizing(yellow or white),powder coating Welded Steel Channel and ...