The EVH-901 dual-module louver provides high-volume intake and exhaust ventilation and protects against water penetration under even the most severe wind-driven-rain conditions. It is AMCA 540- and 550-listed for windborne-debris and high-velocity-wind-driven-rain protection and AMCA-certified for water penetration, air performance, and wind-driven rain. It incorporates a factory-assembled horizontal-blade front module and a vertical-blade rear module.