The DS Duct Support Series is designed specifically for HVAC ductwork. The fixed dimensions give the ability for quick install times. The double C-Ports (C20) provide added support and are made of 100% recycled rubber. The DS Series also come equipped with 4-hole 90-degree fittings for added crossbeam support and 8 hold wing fittings to connect the uprights to the C-port bases. Crossbeam width 40". Crossbeam height up to 36". Base length 20"