This product is absolutely indispensable to anyone with a forced air system. It quickly & reliably seals duct work. The ducts are stabilized and they make fewer cracking/creaking/popping sounds.
Key to installation of Extreme Weather Foil-Tape is:
1) Wear thin suede leather gloves and wipe the duct seams with dry heavy rags - get the loose dust and dirt off. (Suede sticks less to the tape.)
2) A good sharp set of shears will help with the trimming. - You will also need some safe solvent cleaner to clean the shears from time to time.
3) Then carefully start the tape application with the wax-paper liner in place, then slowly peel the backer liner off (in the direction of the seam) and simultaneously press the Foil-Tape down over the seam/seal to be made.
4) With practice and patience, the Foil-Tape makes a very smooth professional (permanent) appearance.
5) Tape the corners too.
6) Importantly, when I encountered those old "repairs" where I incorrectly used the old-fashioned grey fabric "duct" tape, those old "seals" needed to be scraped off. By now, those old "tape" jobs are so deteriorated and dried out, the old tape just falls off. And, yes, the new Extreme Weather Foil-Tape seals up those old seams perfectly.
7) Occasionally, putting an extra sheet metal screw into and through the Foil-Tape seal, is strongly recommended in those applications where it is critical that the sheet-metal is properly self supporting and won't separate from a device or main duct run. Always provide good strapping support for the duct work.
8) Carefully Foil-Tape sealed duct seams, makes it much, much easier to slide duct-insulation products around the ducts.
9) Well taped systems results in much more efficient heating, cooling, and offers dust & noise reduction.