3M Aluminum Foil Tape 3340, 2.5" x 50 yd, 4.0 mil, Silver, HVAC, Sealing and Patching Hot and Cold Air Ducts, Fiberglass Duct Board, Insulation, Metal Repair is a Adhesives Sealants & Lubricants option for everyday use, business supply needs, resale shelves, or household stocking. Review product size, pack count, and shipping details before checkout.