While featuring anchorless system that conserves time and simplifies installation by preventing need to penetrate wall, ECD-545-MD and ECV-645-MD provide performance needed in hurricane-prone regions across USA. Both models are listed for AMCA 540 (impact resistance) and AMCA 550 (high-velocity, wind-driven rain), and neither requires additional damper to pass AMCA 550. Both louvers also bear AMCA seal for water penetration, air performance, and wind-driven rain.