The DSA Duct Support Series is designed specifically for HVAC ductwork. The included telescopic crossbeam allows for easy size adjustments. The bases feature vari-angle C-Ports which adapt to any roof pitch and are made of 100% recycled rubber. C-Ports can adhere to any roof membrane using approved adhesives (if required). Note: Vertical strut not included. Min. Width 18 inches, Max. width 31 inches. Length 10 Inches