Quarrix 58785 Rigid Roll Plus Shingle-Over Ridge Vent, 9" x 20'Shingle Over Rolled Ridge Vent provides continuous ventilation while keeping out nature's worst elements. Draws fresh air from soffit vents, exhausting hot, moist air through the ridge line to create a balanced ventilation system. Patented StormStop technology keeps out wind driven rain, snow, and dust without the need of a baffle. High density polyethylene is virtually unbreakable; won't crack, curl, or expand. Gun nailable. Secure vent and cap