Rigid Roll Plus 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. In extreme weather conditions, damaging elements that could enter into the vent are blocked by the StormStop membrane, a revolutionary spun bound material that keeps moisture out while allowing a constant airflow. Durable corrugated plastic material enables the use of a coil nail gun and doesn"t crush when nailed. Adapts easily to pitches of 2 1/2 to 20/12. Foam end caps are included. Lifetime manufacturer warranty. Low profile. 5/8" thick, 11 1/4" wide, and 13" net free air/square inches. 20" rigid roll.