Flex Seal Pro Series Extreme Roof Tape is a super-strong, rubberized waterproof tape engineered for professional-grade roof repairs and tough sealing jobs. It's extra--thick, flexible backing conforms to uneven surfaces, instantly sealing out water, air, and moisture, even in extreme weather conditions. Perfect for roofs, shingles, flashing, vents, skylights, chimneys, gutters, and more.