The pin-lock AAO control damper is designed with a .080 extruded aluminum hat shaped frame and a single thickness blade that has an intergral section in the blade to accept the ½" spline shaft.

The extruded aluminum spline shaft turns effortless in the double sealed bearings (Celcon inner and polycarbonate outer). The AAO is equipped with both blade and jamb seals of extruded silicone material.