MaxxAir XXBF2430DUCT Nylon Collapsible Duct, 128" For use exclusively with MaxxAir Pro series 30 in. and 24 in. fans Can be used for both exhaust and ventilation Collapses for storage to an easy to store 36 in. x 26 in. x 3 in. package Made of a durable 210D nylon Not for use with flammable vapors