The Van Mark Trim-A-Slitter Perf Combo SCI24HD is designed to slit, stiffen, or perforate roofing steel, aluminum, zinc, or copper. This system comes with 4 knives that allow two cuts with each pass, as well as a perforator die set that allows for perforation. SCI24HD has an adjustable folding feed trade guides with aluminum rollers to ensure that varying widths of metal are quickly squared up for accurate slitting, rib-forming, or perforating. This slitter designed by Van Mark adds rigidity to your metal with a slightly raised rib and add a decorative shadow line to wider fascia and frieze board.