Internal aerodynamic curved baffles. 18 square inches of net free ventilating area per lineal foot. External perpendicular omni baffles. Weatherproof under-lapping joint. Four drain holes per foot per side. External venturi baffle. Pre-formed to 3/12 pitch. 10 supported nail holes. Alignment tabs. External water shield. Slot width guide lines. Adjusts from 2/12 to 16/12 roof pitches. Co-polymer materials. Limited lifetime warranty- the engineered material guarantees it will last as long as your shingles. No connectors required. Molded fanfold end plugs - no accessories or alterations needed. Miami Dade County Approved 11-0602.03. 95 CFM at wind velocity of 3 MPH; 235 CFM at wind velocity of 8 MPH; 430 CFM at wind velocity of 15 MPH.