Do it Best 1.87 In. x 60 Yd. Professional Duct Tape, Silver

Multi-purpose extra-strength energy saving cloth. Multipurpose. Use on heating and air conditioning ducts and much more. Airtight and waterproof. Silver. 10 mil (thousandth of an inch) thick.
Extra Heavy Duty Duct Tape designed for permanent and critical repairs
Super strong but still easy to tear
Works on a variety of surfaces including both rough and smooth
Designed to conform to irregular surfaces
Moisture resistant