Can be installed with a pneumatic nail gun or hammer. Internal aerodynamic curved baffles. External perpendicular Omni baffles. Weatherproof underlapping joint. Four drain holes per foot per side. 11 sq-in of net-free ventilating area per lineal foot. External venturi baffle. Adjusts from 2/12 to 16/12 roof pitches. Limited lifetime warranty, the engineered material assures it will last as long as your shingles. Nail holes marked every 6 in supported every foot. Molded nail lines and centerline. Alignment tabs. External water shield. Slot width guide lines. Molded fanfold end plug. Miami Dade County Approved 13-0701.10. 52 cfm at wind velocity of 3 mph, 148 cfm at wind velocity of 8 mph, 283 cfm at wind velocity of 15 mph.