PERMA-VENT RIDGE VENTILATION SYSTEM combines air-flow technology with the reliability of an all-metal makeup for a system that is unmatched and can be adapted for use with virtually any roofing system. The pierced holes in the .032" thick aluminum base provide maximum airflow while the internal baffles guard completely against infiltration by rain and snow. The Ridge Cover can be formed from steel, aluminum, or copper to match or coordinate with any roofing system. Perma-Vent is custom-formed to meet the roof pitch of each application.