Cascade Series® Two-stage louvre achieves Class A 100% effective rain defence, Class 2 aerodynamics and 50% free open area. The double interlocking blades ensure 100% effective rain defence with reasonable pressure drops for a two-stage louvre. This aerodynamic louvre profile provides a good balance between these two compromising factors of rain defence and airflow while also ensuring zero vision screening. The Cascade Series® two-stage louvre can be supplied in pre-fabricated panels or as a continuous louvre.