Duct Storage Bag, Construction Polyester, For Use With 12 In., 16 In., 20 In. Confined Space Duct, Color Black, Includes Double Zipper, Reinforced Carry Handle, and Shoulder Strap Confined-Space Blowers, Fans, and AccessoriesDesigned for positive and negative ventilation.Confined-Space AccessoriesIndividual components to help design a system to address specific needs.