Air Vent MRV20 is a ridge vent designed to provide constant airflow along the entire underside of the roof to remove heat and moisture. This helps extend the life of shingles and the roof structure. It's easy to install, with a coil of roofing nails provided with every roll. The non-woven, non-wicking matting material is UV stable and won't corrode, rust, or turn brittle. It also helps prevent snow, rain, and insects from getting into the attic.