Designed for the professional contractor and DIYer， Ace HVAC duct tape is a durable， heavy-duty tape that works on both rigid and flexible ductwork. With a durable construction combining the protective benefits of aluminum with the superior adhesive of Ace duct tape， this flex foil tape is ideal for sealing both cold and hot air ducts. This silver adhesive tape is approved for use on metal air ducts and for working with a broad range of temperatures for flexible and rigid ducting. Just apply HVAC Duct Tape in strips along open or overlapping seams between duct paneling， joints， vents and more.