When it comes to the protection of ducts in commercial applications GLT Products offers 2 types of Firestop Blankets. The 3M Fire Barrier Plenum Wrap 5A is a fire resistant wrap consisting of a patented inorganic blanket encapsulated with a scrim-reinforced foil. Our other solution, 3M Fire Barrier Duct Wrap 615+ is the only fire rated duct wrap you need for code required protection of grease and air ducts.