MARK 16 PANEL is Mechanically Seamed, covers 16" and is comprised of two major ribs 2" high. This standing seam system’s high interlocking ribs provide exceptional strength and dramatic appearance, while reducing a potential source of roof leaks by eliminating fastener penetrations. Mark 16 is available in 24 ga. or 22 ga. galvalume or galvanized panel substrate. All galvanized material has G-90 coating and conforms to A.S.T.M. A653-98 SS Grade 40 (40 000 lb. min. yield strength) or galvalume coating conforming to A.S.T.M. A-792-97 Grade 40.