Created specifically for spiral ducts, AP Spiralflex™ is a 100 percent fiber-free, elastomeric duct liner. It eliminates the need for encapsulating films or heavy dual-wall systems, said the company. Made from highly conformable elastomeric foam, the duct liner easily can be cut with a sharp knife. The Microban® antimicrobial and formaldehyde-free duct liner’s smooth and flexible backing fits snugly against the duct wall without gaps. Installation involves forming a correctly sized AP Spiralflex tube with one glued and taped seam, then inserting it into spiral duct sections. It is available in 48-inch wide, (nominal) 1-inch-thick rolls.