The batten bridge is 63.5mm wide and has three holes for mounting into the batten if desired. The 10mm x 20mm rail attachment slot accepts 5/16-inch or 3/8-inch bolts. Use the 1/4-inch or 5/16-inchSolar Mounting Screws in the 9mm mounting screw slots. Works with all stone coated steel roof profiles including Decra, Boral, and Isaiah roofing.