List damper as duct size – damper will be undersized 1/4″
The RBD is our round back draft damper designed to fit inside the pipe.
The welded 2″ deep frame is undersized 1/4″ for easy installation. The .025 aluminum
butterfly style blades are attached to the damper using 1/4″ plated rod and bronze bushings.
Attached to the blades is a spring closure that seals the blade up tightly against a neoprene gasket.