3M High Temperature Flue Tape measures 1-1/2 inches x 15 feet and can be used up to 600 degrees Fahrenheit. It's quick and easy to install and stops leaks from seams in hot air ducts. 3M Weather Sealing Tapes are innovative solutions for reducing heating costs and saving energy. 3M Tapes are all designed for quick, easy installation. There is a product for almost every need, from sealing cracks and drafts around windows and doors to stopping leaks from hot air ducts.