Low profile fiber mat permits maximum airflow yet prevents water and insect infestation. 3/4" - lowest profile in the industry. No fabric overwrap or filters to clog or deteriorate. Flexible, easy to handle. Conforms to roof pitches from 2/12 to 20/12. 40 year limited warranty. Includes 2-1/2" roofing nails. Cobra hand nailable ridge vent net free area - 16.9 sq. in./linear ft. Cobra gun nailable ridge vent net free area - 14.1 sq. in./linear ft.