GAF TigerPaw 48-in x 250-ft 1,000-sq ft Polypropylene Roof UnderlaymentSynthetic, non woven construction provides at least 600% (ie 7 times) greater tear strength than standard #30 felt in addition to water resistance Helps remove nearly twice as much damaging moisture from your roof deck as the leading synthetic non breathable underlayment Tiger paw roof deck protection resists wrinkling and buckling that can telegraph through your roof shingles and detract from its finished appearance Less chance of blow off, up to