Owens Corning WeatherLock 36-in x 66.7-ft 200-sq ft Polypropylene Roof Underlayment AA10

WeatherLock G Granulated Self-Sealing Waterproofing Barrier provides additional security against leaks caused by storms, wind-driven rain and shingle blow-offs. This product is engineered for asphalt shingles, wood shakes and quarry slate roofs. WeatherLock G acts as a waterproof barrier in the most vulnerable sections of the roof.