Can be installed with a pneumatic nail gun or hammer. Two coils of 1-3/4 in nails provided. External convolute baffles incurved design allows flexibility to roll up and out while maintaining its shape. Can be cut at one foot intervals multiple cut lines eliminates unnecessary scrap. Weather protection and performance with no filter to clog. Molded fanfold end plug. Molded centerline. Nail holes marked every 6 in supported every foot. 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. Miami Dade County Approved 13-0701.11. 52 cfm at wind velocity of 3 mph, 148 cfm at wind velocity of 8 mph, 283 cfm at wind velocity of 15 mph.