Owens Corning WeatherLock Mat 36-in x 66.7-ft 200-sq ft Polypropylene Roof UnderlaymentActs as a second layer of protection under shingles Ideal for all underlayment applications such as full roof deck coverage, eaves, rakes, and valleys Patented Sure Step mat faced design helps provide for a consistent surface, reducing slipping, sticking, and scuffing 40% Lighter than standard mat faced underlayment products, making it easy to load, carry, and install Up to a 30 year limited warranty dependent on the warranty of the Owens Corning